Vysoké učení technické v Brně, Fakulta chemická ......2 7th Meeting on Chemistry and Life...

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7th Meeting on Chemistry and Life 2018. Book of abstracts

Editor: Ing. Petr Dzik, Ph.D.

Nakladatel: Vysoké učení technické v Brně, Fakulta chemická, Purkyňova 464/118, 612 00 Brno

Vydání: první

Rok vydání: 2018

Náklad: 100 ks

ISBN: 978-80-214-5488-0

Tato publikace neprošla redakční ani jazykovou úpravou

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Gold and Silver Sponsors, Partners

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Other Sponsors Donators

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Contents

Plenary and invited lectures .................................................................................................................................. 14

Optoelectronic Stimulation of Cells with Organic Photocapacitors

Eric Daniel Głowacki1 ........................................................................................................................................ 15

Combined Application of Metal Speciation and Omics in Food Quality Assessment

Sara Ramírez-Acosta1,2,3

, Ana Arias-Borrego 1,2,3

, Tamara García-Barrera1,2,3

, José Luis Gómez-Ariza 1,2,3

....... 16

Synthesis and characterization of smart hydrogel systems

Sabine Hild ........................................................................................................................................................ 17

Lipid Driven Nanodomains Are Fluid

R. Šachl, M, Amaro, A. Koukalová, L.Veľas, and M. Hof ................................................................................... 18

PHA - A Biodegradable Plastic To Solve Society Problems?

Ines Fritz 1

.......................................................................................................................................................... 19

Photopolymerization: From Biomaterials to 3D Printing

Robert Liska ...................................................................................................................................................... 20

Biodegradable Polymer Materials: Properties, Applications, and Environmental Fate

Marek Koutný1, Jana Šerá

1, Jan Salač

1 .............................................................................................................. 21

Improved Nitrogen Fertilisers Utilising Humic Material Blends

Biplob K. Saha1, Michael T. Rose

2, Vanessa Wong

3, Timothy R. Cavagnaro

4 and Antonio F. Patti

1*................. 22

Nanostructure of Cementitious Products: A MAS-NMR Approach

Angel Palomo1, Ana Fernandez-Jimenez

1 ......................................................................................................... 23

PHA Workshop ...................................................................................................................................................... 24

Extremophiles – platform strains for sustainable production of polyhydroxyalkanoates

Stanislav Obruca1, Dan Kucera

1, Eva Slaninova

1, Iva Pernicova

1, Petr Sedlacek

1, Filip Mravec

1,

Ivana Marova1, Ota Samek

2, Ladislav Krzyzanek

2, Martin Vanek

1, Adriana Kovalcik

1, Lucie Mullerova

1,

Aneta Chytilova1, Ivana Novackova

1, Olga Kratochvilova

1, Jana Nebesarova

3 ................................................. 25

Biological valorization strategy for converting spent coffee grounds into biopolymers and chemicals

Adriana Kovalcik1, Dan Kucera

1,2, Stanislav Obruca

1,2, Helena Hudeckova

1,2, Ivana Marova

1,2 ........................ 26

Monitoring of biotechnological production of microbial substances using Raman spectroscopy

Ota Samek1, Stanislav Obruča

2,3, Jan Ježek

1, Silva Bernatová

1, Zdeněk Pilát

1, Andrea Hároniková

2,3, Ivana

Márová2,3

, Petr Sedláček2,3

, Dominika Gonová2, Martin Šiler

1, Pavel Zemánek

1 .............................................. 27

Environmental Chemistry and Technology ........................................................................................................... 28

The photocatalytic decomposition of methanol over photocatalyst based on the TiO2

Abouali galedari, N.a, Dubnová, L.

b, Matějová, L.

a, Reli, M.

a, Drobná H.

b, Čapek, L.

b, Kočí, K.

a...................... 29

Urban aerosol: metals as starters of cellular stress?

Hana Barboříková1, Pavel Mikuška

2, Jozef Krajčovič

1 ....................................................................................... 30

Toxicity of Some Nitramines

Karel Bednařík1, Papírek Jan

2 ............................................................................................................................ 31

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Application of Statistical Methods for Assessment of Soil Pollution

Helena Doležalová Weissmannová 1, Silvie Mihočová

1, Petr Chovanec

1, Jan Brzobohatý

1 ........................... 32

Determination of PPD in Hair Dyes Collected from Local Markets in El-Bieda city – Libya

Galal Elmanfe 1,3

, Osama Khreit 2,3

, Omukalthum Abduljalil3 and Enas S. Farag

1 .............................................. 33

Anhydrous ethyl lactate synthesis by transesterification of oligomeric lactic acid

Silvestr Figalla1, Jaroslav Petruj, Tereza Švestková ........................................................................................... 34

Development of New Voltammetric Approach for Determination of Plant Hormones Employing Boron-Doped

Diamond Electrode as a Sensor

Jaromíra Chýlková1, Lenka Janíková

1, Miloš Sedlák

2, Jiří Váňa

2, Renáta Šelešovská

1 ....................................... 35

Distinguishing the PET quality for its recycling

Lucie Kabelíková1, Jiří Kučerík

1 .......................................................................................................................... 36

Removing CO2 from Air Masses by a Pilot-Plant Scubber Equipped With a Spiral Nozzle

Josef Kalivoda1, Tomáš Svěrák

2, Ondřej Krištof

1, Kateřina Mayerová

1 ............................................................. 37

Platinum nanoparticles in the environment and their impact on soil

Renata Komendová1, Michal Berka

1, Jiří Kučerík

1 ............................................................................................. 38

Possibilities of water and energy storage in the environment of fast-growing trees

Kotlík, J., Půčková, H., Levek, P., Mikšík, F., ...................................................................................................... 39

Linking soil microbial quality indicators and thermo-oxidative stability

Jiří Kučerík1, Karel Svatoň

1, Stanislav Malý

2, Martin Brtnický

3, Christian Siewert

4 ........................................... 40

System of efficient use of heat, water and electricity in family houses

Petr Levek, Milada Vávrová, Josef Kotlík, Helena Půčková, František Mikšík, Silvie Kotlíková ......................... 41

Preliminary Investigation into the Stimulation of Plant Growth Promoting Bacteria (Pgpb) by Soil Amendment

With a Commercial Humic Acid

Karen Little1, Han Ming Gan

2, Michael Rose

3, William Roy Jackson

1, Timothy Cavagnaro

4

and Antonio Patti1. ........................................................................................................................................... 42

Assessment Adsorption behavior of K-Humat (Tki- Hümas) on carbon nanotubes from soil by provided E4/E6

ratios in different incubation times

Abdelbagi Mohamedelnour1, Muhittin Onur Akça

1, Sonay Sözüdoğru Ok

1 ..................................................... 43

Analysis of organic compounds in biochar produced by pyrolysis of sludge

Ludmila Mravcová1, Flávia Bittencourt Moré

2, Jakub Raček

3, Jan Ševčík

3, Josef Čáslavský

1,

Milada Vávrová1 ................................................................................................................................................ 44

Possible solutions for process monitoring on the wastewater treatment plants

Michal Petruľák1, Josef Čáslavský

1 .................................................................................................................... 45

The Role of Alkalis In Hydraulic Mixtures

Prochazka, L. ..................................................................................................................................................... 46

Environmental aspects of fast growing trees

Puckova, H., Kotlik, J., Levek, P., Miksik, F., Kotlikova, S., Caslavsky, J. ............................................................ 47

Artificial sweeteners in water

Martina Repková, Nikola Dalajková, Libuše Vítková ......................................................................................... 48

Spectrophotometric determination of chlorophyll in tests of phytotoxicity

Veronika Řezáčová, Petra Rábová, Helena Zlámalová Gargošová .................................................................... 49

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From Chemistry to Technology - Biomass Gasification Product Gas Cleaning and Utilization

Petr Seghman1, Tomáš Jirout

1, Lukáš Krátký

1 ................................................................................................... 50

Phthalates concentration in Anzali wetland sediments, Iran

Fatemeh Shariati1*, Mohammadjavad Mostafaloo

1, Shahab Shariati

2, Shayan Shariati

3 ................................ 51

The use of ion exchangers for preconcentration of platinum group metals

Jiří Sýkora1, Renata Komendová

1 ...................................................................................................................... 52

Determination of antidepressants and psychoactive drugs in waste water

Vávrová Milada, Švestková Tereza, Mravcová Ludmila, Landová Pavlína, Křivánková Zuzana,

Kočnar Michal ................................................................................................................................................... 53

Separation of air pollutants using different types of scrubbers

Jaroslav Vlasák 1, Tomáš Svěrák

1, Lukáš Drevený

1, Josef Kalivoda

1 .................................................................. 54

Ecotoxicity evaluation of fire extinguishing agents

Helena Zlámalová Gargošová1, Barbora Jabandžievová

1 .................................................................................. 55

Czech and Slovak Food Science Meeting .............................................................................................................. 56

Lignans in foods and food fortification using 7-HMR

Josef Balík1, Pavel Híc

1, Jana Kulichová

1, Jan Tříska

2, Naděžda Vrchotová

2, Milan Houška

3 ............................. 57

DNA binding properties of p53 mutant R249S protein induced by exposure to aflatoxin in food

Václav Brázda1,2

, Natália Vadovičová1, Eva B. Jagelská

2, Jan Coufal

2, ............................................................... 58

Analysis of yeast exoproducts related to antifungal activity of Metschnikowia pulcherrima

Emília Breierová, Dominika Šoltésová, Barbora Stratilová and Vlasta Sasinková ............................................ 59

Positioin of Food Fraud Prevention and Food Defence in Food Safety Management Systems

František Buňka, Michaela Černíková ............................................................................................................... 60

Biotechnological Preparation of Functional Cereals-Based Food and Feed

Milan Čertík1, Tatiana Klempová

1, Ondrej Slaný

1, Miroslav Janák

1, Slavomír Marcinčák

2 ................................ 61

Validation of diffusive gradient in thin films technique for determination of mercury in fish sauce

Pavel Diviš 1, Marek Reichstädter

1, Aneta Habartová

1 and Jakub Kříkala

1 ....................................................... 62

Diversity of Yeasts Colonizing Aboveground Plant Organs of Fruit Trees and the Soil Related

to these Trees

Hana Dudášová, Renáta Vadkertiová ............................................................................................................... 63

Comparison of sensitivity of DNA biochip and Real Time PCR for pork DNA in meat products

Zuzana Drdolová1, Jozef Golian

2 ....................................................................................................................... 64

Maldi TOF Analysis For Verification of Collection Yeasts And Classification of New Isolates

Ágnes Horváthová1, Natália Čurillová

2, Monika Vadkertiová

3, Laura Vyšehradská

4, Ivana Márová

2, Hana

Dudášová1, Barbora Stratilová

1,5 ....................................................................................................................... 65

Effects of conventional heating on fatty acids profile of virgin and refined olive oil

Dani Dordevic1, Lucia Hodulová

1, Simona Jančíková

1, Sanja Ćavar Zeljković

2,3 ................................................ 66

The effect of final heating on the concentration of phthalic acid esters in sous-vide products

Marcela Jandlová1, Alžbeta Jarošová

2, Josef Kameník

3 .................................................................................... 67

Pigmented yeasts as biotechnological factories for bioproducts and biofuels

Márová I.1, Szotkowski M.

1, Vanek M.

1, Byrtusova D.

1, Rapta M.

1, Haronikova A.

1, Certik M.

2,

Shapaval V 3

....................................................................................................................................................... 68

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Analytical and chemometric tools used for fruit juices authenticity evaluation

Martin Polovka1, Blanka Tobolková

1, Elena Belajová

1, Mária Kopuncová

1,, Ján Durec

2 ................................... 69

Influence of the postfermentation technologies on selected chemical components of czech lager beer

Jaromír Pořízka1, Dominika Vopelková

1, Václav Štursa

1, Milena Vespalcová

1, Pavel Diviš

1 ............................. 70

Processing of pomace from chokeberry and elderberry

Milena Vespalcová1, Tereza Lošková

2, Zuzana Jurečková

2, Václav Štursa

2, Jaromír Pořízka

2, Pavel Diviš

2 ...... 71

Influence of aroma compounds on sensory quality of processed cheese analogues

Eva Vítová, Michal Sýkora, Martina Mahdalová, Kateřina Sůkalová ................................................................ 72

Is rapeseed oil suitable for frying French fries?

Eva Vítová, Michal Sýkora, Martina Mahdalová, Kateřina Sůkalová ................................................................ 73

Physical Chemistry & Life with Special Session on Advanced Fluorescence Techniques ..................................... 74

Influence of surfactant concentration on hyaluronan hydrogel microstructure characteristics

measured by FRET

Zuzana Adamcová1, Filip Mravec

1, Miloslav Pekař

1 .......................................................................................... 75

Förster Resonance Energy Transfer between Perylene and Fluorescein in Cationic Micellar Solutions

Petra Holínková1, Filip Mravec

1, Miloslav Pekař

1 .............................................................................................. 76

Preparation and research of cosmetic emulsions from solid TiO2 and emulsions prepared

from dispersion of TiO2

Sabina Jarabkova1, Marcela Lastuvkova

2, Adam Jugl

3, Tomas Velcer

4, Jiri Smilek

5 .......................................... 77

Study of Electrostatic Interactions between Hyaluronan and Amino Acids

Adam Jugl1, Miloslav Pekař

2, Hejná Jana .......................................................................................................... 78

Study of flow properties of powders in pharmaceutical industry

Pavel Kolesa1 ..................................................................................................................................................... 79

Sorption of Water Humidity by Selected Biopolymers by Means of Microcalorimetry

Jitka Krouská1, Tomáš Bola

2, Vojtěch Enev

1, Miloslav Pekař

1,2 ......................................................................... 80

Complex characterization of agarose hydrogels

Marcela Lastuvkova1, Milan Kracalik

2, Jiri Smilek

1 ............................................................................................ 81

Fluorescence Techniques in Hydrogel Characterization

Filip Mravec ...................................................................................................................................................... 82

Design of nanostructure models using grammatical evolution

Pavel Osmera senior1, Daniel Zuth

1, Anna Kucerova

1, Pavel Osmera junior

2, Monika Dosoudilová

1, Jan

Muller1, Tomas Marada

1, Ladislav Dobrovsky

1 ................................................................................................. 83

What keeps polyhydroxyalkanoates in bacterial cells amorphous? A contribution from stress-response

experiments

Petr Sedláček1, Eva Slaninová

1, Stanislav Obruča

1 ............................................................................................ 84

Effects of Hydration of Sodium 3-Hydroxybutyrate on Phase Transitions Connected to Cryoprotectivity Of

Microorganisms

Eva Slaninová1, Vitaly Kocherbitov

2, Petr Sedláček


1 ........................................................... 85

Light scattering techniques in the study on the formation of the interactions between polysaccharides and

surfactants

Michal Kalina1, Šárka Sovová

1, Miloslav Pekař

1 ................................................................................................ 86

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Organic Electronics & Photochemistry and Photocatalysis .................................................................................. 87

Modification of Photocatalyst Morphology by Ball-milling and its Impact on the Physicochemical

Properties of Wet Coated Layers

Petr Dzik1, Michal Veselý

1, Tomáš Svoboda

1 .................................................................................................... 88

Bioelectronical device for electrostimulation of stem cells

Jiří Ehlich1, Ota Salyk

1, Stanislav Stříteský

1, Lukáš Omasta

1, Eva Šafaříková

2, Jan Víteček

2, Lukáš Kubala

2,

Martin Vala1, Martin Weiter

1 ............................................................................................................................ 89

Improvement of Performance of Screen-Printed Electroluminescent Device by Reducing the Thickness of

Dielectric Layer

Michal Hrabal1, Petr Dzik

1, Lukáš Omasta

1, Martin Vala

1, Martin Weiter

1 ....................................................... 90

Printed Perovskite Solar Cells with Carbon Back Electrode

Matej Hvojnik, Michal Hatala, Barbora Krištofovičová, Pavol Gemeiner, Milan Mikula .................................. 91

Optoelectronic control of single cells using organic photocapacitors

Marie Jakešová1, Malin Silverå Ejneby

2, Tony Schmidt

3, Johan Brask

2, Vedran Derek

1, Magnus Berggren

1,

Rainer Schindl3, Fredrik Elinder

2, Daniel Simon

1, Eric Daniel Głowacki

1 ........................................................... 92

Implementation of polycyclic cycloalkane systems: a path to high-performing, soluble, versatile and

sustainable organic semiconducting materials

Alexander Kovalenkoa, Cigdem Yumusak

b, Patricie Heihrichova

a, Stanislav Stritesky

a, Martin Vala

a, Martin

Weitera Niyazi Serdar Sariciftci

b and Jozef Krajcovic

a, ...................................................................................... 93

Alkyl substitutions a powerful tool for tailormade properties of soluble and versatile organic semiconducting

materials

Jozef Krajčovič1, Alexander Kovalenko

1, Martin Vala

1, Martin Weiter

1, Cigdem Yumusak

2, Niyazi Serdar

Sariciftci2 ........................................................................................................................................................... 94

Conductive polymers integrated into a textile matrix designed for sensor elements

Kubáč, L., Pretl, S., Josefík, F., Martinková, L., Hamacek, A. ............................................................................. 95

Time-resolved kinetics of excitons, polarons and polaron pairs in organized thin films of conducting

polymers

Miroslav Menšík1, David Rais

1, Jiří Pfleger

1, Petr Toman

1................................................................................. 96

Screen Printed Biocompatible Photoresist as a mean to Enhance Performance of Organic Electrochemical

Transistors

Lukáš Omasta1, Jiří Ehlich


1, Michal Hrabal

1, Ota Salyk

1, Martin Vala

1, Martin Weiter

1,

Milan Matejka2 ................................................................................................................................................. 97

High-k dielectrics for organic electronic devices

Jiří Pfleger, Francesco Piana, Bartosz Paruzel, Yadu Ram Panthi ...................................................................... 98

Organic Solar Cells with an Inkjet Printed Hole-Extracting Graphene Oxide Layer

Jan Pospisil1, Alexander Kovalenko

1, Oldrich Zmeskal

1, Martin Vala

1 .............................................................. 99

Flashing light at the “dark” triplet states in organic semiconductors

David Rais,1 Jiří Pfleger,

1 Petr Toman,

1 Miroslav Menšík,

1 Yaduram Panthi,

1 Martin Vala,

2 Jozef Krajčovič,

2

Stanislav Stříteský,2 Martin Weiter

2 ................................................................................................................ 100

New bio-inspired organic semiconductors for bio-organic electronics

Jan Richtar1, Alexander Kovalenko

1, Martin Weiter

1, and Jozef Krajčovič

1 .................................................... 101

Charge Carrier Mobility in Lamellar Structure of Conjugated Polymers

Petr Toman, Miroslav Menšík, Jiří Pfleger ...................................................................................................... 102

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Disposable Printed Ozone Dosimeter

Michal Veselý, Petr Dzik, Zuzana Petříčková .................................................................................................. 103

Contact resistance effects in organic field-effect transistors

Martin Weis .................................................................................................................................................... 104

Artificial Photosynthesis: Learning from Nature

Dong Ryeol Whang ......................................................................................................................................... 105

Organic field effect transistors based on hydrogen-bonded semiconductor pigments

Cigdem Yumusak ............................................................................................................................................ 106

Inorganic Materials ............................................................................................................................................. 107

Hybrid binder from recycled concrete powder and BPCKD

Bílek, V. ........................................................................................................................................................... 108

Preparation and characterization of electroless Ni-P coating on wrought ZE10 magnesium alloy

Martin Buchtík1, Petr Kosár

1, Jakub Tkacz

1, Pavel Doležal

1,2, Jaromír Wasserbauer

1 ..................................... 109

Use of infrared spectroscopy as a tool for the identification and analysis of inorganic materials

Jan Hajzler, Tomáš Opravil, Petr Ptáček, Petr Sedláček .................................................................................. 111

Durability of basalt fibres under the alkaline conditions

Hrubý, P., Kalina, L., Másilko, J., Pořízka J. ...................................................................................................... 112

Alkali-activated slag-based systems with cement bypass dust incorporation

Lukáš Kalina, Vlastimil Bílek Jr., František Šoukal, Tomáš Opravil .................................................................. 113

Application of the theoretical knowledge of material engineering to building practice

Konarik, J. ........................................................................................................................................................ 114

Anhydrite stabilization in refractory materials

Kotrla Jan, Ing., Šoukal František, doc., Ph.D., Švec Jiří, Ing., Ph.D., ............................................................... 115

Resistance of cementitious composites against ballistic loading

Koutný Ondřej, Kratochvíl Jiří, Krátký Josef .................................................................................................... 116

Basics of ballistic protection design

Jiří Kratochvíl, Ondřej Koutný, Jiří Švec, Josef Krátký...................................................................................... 117

Ash – the raw material base for the future

Marko M., Opravil, T., Šoukal F., Pořízka J. ..................................................................................................... 118

Development of heavyweight concrete for an eventual gamma and neutron-rays shielding application

Janette Dragomirová, Martin Palou................................................................................................................ 119

Formation of clinker containing lithium

Theodor Staněk1, Alexandra Rybová

2, Anežka Zezulová

3, Martin Boháč

4 ...................................................... 120

Differences in use of isothermal and isoperibolic calorimetry to assess the effect of zinc on hydration of

cement blended with ground blast furnace slag and silica fume

Pavel Šiler1, Iva Kolářová

1, Jiří Dobiáš

1, Radoslav Novotný

1, Jiří Másilko

1, Jiří Švec

1, Jan Bednárek

1, Martin

Janča1, Tomáš Opravil

1 .................................................................................................................................... 121

Portland clinker characterization by scanning electron microscopy with BSE, EDS, WDS and EBSD

Šoukal, F.1, Opravil, T.

1, Ptáček P.

1, Staněk T.

2 ................................................................................................ 122

Porous hydroxyapatite/alumina composites intended for bone tissue engineering

Jan Vojtisek, Eva Bartonickova, Juliana Drabikova, Jaromir Porizka ............................................................... 123

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Functional Materials ........................................................................................................................................... 124

Processing stabilization of poly(3-hydroxybutyrate)/poly(lactic acid) blends with

oligomeric carbodiimide

Veronika Melcova1, Radek Prikryl

1, Premysl Mencik

1, Jiri Tochacek

2 ............................................................. 125

Biodegradable composite materials based on poly(3-hydroxybutyrate) for 3D printing applications

Premysl Mencik1, Veronika Melcova

1, Radek Prikryl

1, Sona Kontarova

1, Jano Bockaj

2, Pavol Alexy

2 ............ 126

Adhesion and Mechanical Properties of a-CSi:H Thin Films Prepared from Tetravinylsilane Monomer by

Plasma Polymerization

Tomas Plichta1, Martin Branecky

1, Vladimir Cech

1 ......................................................................................... 127

Synthesis of lactic acid-based thermosetting bio-polyester

Tomáš Porubský1, Mikael Skrifvars

2, Jaroslav Petrůj

1 ..................................................................................... 128

The Effect of Bioactive Additives on Morphology and Biological Properties of Collagen-Based Nanostructured

Resorbable Skin Substitutes

Lucy Vojtova1,2

, Johana Babrnakova1, Veronika Pavlinakova

1, Lucie Vistejnova

3, Veronika Stepankova

4, Eva

Filova5, Martin Knoz

6,7,8, Bretislav Lipovy

6,7, Jakub Holoubek

6, Zdenek Pavlovsky

6, Martin Faldyna

9, Eduard

Göpfert9, Jiri Damborsky

10, Vanessa Hearnden

11 ........................................................................................... 129

Young Researchers Forum .................................................................................................................................. 130

Cytotoxic activity of liposome particles with natural source of antioxidants for food

and cosmetic application

Jitka Bokrova1,2

, Ivana Maslonkova2, Renata Pavelkova

1,2, Petra Matouskova

1,2, Ivana Marova

1,2 ................ 131

High-ordered adamantane-substituted industrial organic dyes for organic semiconducting materials

Martin Ciganek1, Jozef Krajcovic

2.................................................................................................................... 132

ANTIBACTERIAL 3D POROUS COLLAGEN SCAFFOLDS FOR SOFT TISSUE REGENERATION

Jana Dorazilová1, Johana Babrnáková

2, Kristýna Šmerková

3, Pavel Kopel

3, Silvia Kočiová

3,

Pavel Diviš4, Vojtěch Adam

3, Lucy Vojtová

2 .................................................................................................... 133

Polylysine Coated Magnetic Nanoparticles As A Tool For DNA Isolation From Real Samples

Lenka Fialova1, Alena Spanova

1, Bohuslav Rittich

1 ......................................................................................... 134

Characterization of adsorption properties of probiotic bacteria

Eva Fryšová1, Klára Černá

1, Eva Slaninová


1, Aneta Chytilová

1 .......................................... 135

The Effect Of Antibacterial Selenium Nanoparticles On The Properties Of Polymer-Phosphate

Bone Fillers

Veronika Grézlová1, Lenka Michlovská

2, Kristýna Šmerková

3, Pavel Kopel

3, Vojtěch Adam

3, Silvia Kočiová

3,

Petr Bábor4, Pavel Diviš

5, Petr Poláček

2, Lucy Vojtová

2 .................................................................................. 136

The comparison of platinum metal contaminations of the environment in Brno, Czech Republic

and Moscow, Russia

Stanislav Ježek1, Renata Komendová

1 ............................................................................................................ 137

Improving the Stability of Perovskite Solar Cells

Matouš Kratochvíl1, Dávid Strachala

2, Adam Gajdoš

2, Martin Weiter

1 .......................................................... 138

Thermal properties of electro insulating papers

Lucie Marackova1, Veronika Melcova

2, Josef Samek

3, Oldrich Zmeskal

4 ........................................................ 139

Single Cell Analysis And Use Of Autofluorescence In Pha Synthesising Bacteria

Lucie Müllerová 1,2

, Stanislav Obruča 1,2

, Filip Mravec 1, Kateřina Bílková

1 ................................................... 140

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THE USE OF NATURAL EXTRACTS IN COSMETICS AND SUBSEQUENT DETECTION OF PLANT DNA USING MOLECULAR DIAGNOSTIC

METHODS

Renata Pavelková1, Denisa Romanovská

2, Monika Plachá

2, Anna Plášková

2, Petra Matoušková

1, Andrea

Hároniková1, Ivana Márová

1 ........................................................................................................................... 141

Screening of biosurfactants excretion among selected bacteria

Iva Pernicová1,2

, Olga Kratochvílová1, Dan Kučera

1,2, Stanislav Obruča

1,2 ...................................................... 142

Stability of methylated humic acids

Jan Rybárik1, Vojtěch Enev

1, Martina Klučáková

1 ........................................................................................... 143

Organic Transistors Towards Bio-electronic Applications

Stanislav Stříteský1, Lukáš Omasta

1, Jiří Ehlich

1, Šárka Tumová

1, Aneta Marková

1, Eva Šafaříková

2, Jan

Víteček2, Lukáš Kubala

2, Lubomír Kubáč

3, Ota Salyk

1, Martin Vala

1, Martin Weiter

1 ..................................... 144

Monitoring of the fatty acid content in Swiss type cheese

Michal Sýkora, Eva Vítová ............................................................................................................................... 145

Study of potencial use and production of carotenoid, lipid enriched biomass using extremophilic algae

isolated from Rio Tinto, Spain

Martin Szotkowski, Carlos Vilchez Lobato, Ivana Márová .............................................................................. 146

Removal of sulfonamides antibiotics by wood-decay fungi from water matrix

Suková Petra1, Žižlavská Adéla

2, Švestková Tereza

1, Vávrová Milada

1 ........................................................... 147

Modelling of Bioelectronic devices

Truksa, J. ......................................................................................................................................................... 148

Modification of PEDOT:PSS Surface by RGD Peptide

Šárka Tumová1, Romana Malečková

1, Vojtěch Enev


1, Martin Vala

1, Martin Weiter

1..... 149

THIXOTROPIC POLYMER-COMPOSITE BONE CEMENT

Kristýna Valová1, Lenka Michlovská

2, Klára Částková

3, Lucy Vojtová

2 ............................................................ 150

On Mixing and Separation During Polyhydroxyalkanoates Extraction – Yield and Purity Optimization

Martin Vanek1, Libor Tomala

2, Martin Szotkowski

1, Ivana Novackova

1, Stanislav Obruca

1 ........................... 151

Psychoactive pharmaceuticals in water

Petra Venská1, Martina Repková

2, Milada Vávrová

3 ....................................................................................... 152

Analysis of Betaglucans in selected commercial products and higher funghi with their possibility use in

pharmaceutical industry.

Marie Vysoká1, 2

, Dana Byrtusová 1, 2

, H. Thra Phan2, P. Matoušková

1, 2, I. Márová

1, 2 .................................. 153

14

Plenary and invited lectures

15

Optoelectronic Stimulation of Cells with Organic Photocapacitors

Eric Daniel Głowacki1

1 Laboratory of Organic Electronics, ITN Campus Norrköping, Linköping University, 60221,

Norrköping, Sweden, E-mail: [email protected]

Keywords: bioelectronics, neural stimulation, organic electronics, photochemistry

We work on nanoscale semiconducting optoelectronic systems that form close interfaces with living cells. The aim is to create devices that transduce impulses of light into signals that can influence the electrophysiology of the cell, while of course preserving its long-term viability. Organic semiconducting nanocrystalline materials offer the possibility of fabricating such devices such as to be minimally invasive in the biological context. Moreover, many organic semiconductors are nontoxic and safe, and softer than their inorganic counterparts.

The core device concept for stimulating is the organic electrolytic photocapacitor (Figure 1, left). The devices comprise a trilayer of metal and p and n semiconductors, 50-80 nm total device thickness [1]. When illuminated in physiological solution, these metal-semiconductor devices charge up, transducing light pulses into localized displacement currents that are strong enough to stimulate cells. The devices are freestanding, requiring no wiring or external bias, and are stable in physiological conditions. We have systematically evaluated the ability of photocapacitor devices to alter the cell membrane potential of single nonexcitable cells, generate action potentials in neuronal cell cultures, and finally stimulate explanted light-insensitive

embryonic retinas. The standard photocapacitor devices we have optimized control electrophysiological processes using infrared light pulses – which can safely penetrate tissue. We have devised implantable prototypes, focusing primarily on the application of retinal implants for restoring vision to blind patients.

The second concept we work on is tailoring the nanocrystalline interface with the cell membrane. This is critical for promoting or inducing desired cell growth and attachment, and a high surface interface translates to effective optoelectronic stimulation. One of the results of our efforts is the hedgehog hierarchical microcrystal (Figure 1, right). Hedgehog crystals consist of “needles” of 20-50 nm size. These are fairly rigid monocrystals that are surface functionalized with aliphatic organic ligands. These needles self-assemble into hierarchical microstructures, which are held together by relatively weak van der Waals forces. These are soft and pliable and are excellent at forming intimate interfaces with living cells [2]. The material constituting the hedgehogs is semiconducting and photoactive, and thus suitable for transducing optical signals into membrane potential changes. These can be measured using patch clamp techniques.

Figure 1: (left) Schematic of the capacitive coupling mechanism between the p-n junction photocapacitor device and the cellular membrane. The metal-p-n combination leads to photoinduced depolarization of the membrane. (right) Cell culture of human embryonic kidney cells shown over time as they attach and form close interfaces to hedgehog hierarchical microcrystals.

References [1] Rand, D.; Jakešová, M.; Lubin, G.; Vebraite, I.; David-Pur, M.; Đerek, V.; Cramer, T.; Sariciftci, N. S.; Hanein, Y.; Głowacki, E. D. Direct Electrical Neurostimulation with Organic Pigment Photocapacitors. Adv. Mater. 2018, DOI: 10.1002/adma.201707292 [2] Sytnyk, M.; Jakešová, M.; Litviňuková, M.; Mashkov, O.; Kriegner, D.; Stangl, J.; Nebesářová, J.; Fecher, F. W.; Schöfberger, W.; Sariciftci, N. S.; et al. Cellular Interfaces with Hydrogen-Bonded Organic Semiconductor Hierarchical Nanocrystals. Nature Commun. 2017, 8, 91.

Acknowledgement We are grateful for funding from the Wallenberg Center for Molecular Medicine at Linköping University.

16

Combined Application of Metal Speciation and Omics in Food

Quality Assessment Sara Ramírez-Acosta1,2,3, Ana Arias-Borrego 1,2,3, Tamara García-Barrera1,2,3, José Luis Gómez-Ariza 1,2,3

1 Department of Chemistry, Faculty of Experimental Sciences. University of Huelva, Huelva, Spain,

[email protected] 2 International Agrofood Campus of Excellence International ceiA3, University of Huelva, Huelva,

Spain 3 Research Center of Natural Resources, Health and the Environment (RENSMA), Huelva, Spain

Keywords: Metal speciation, metallomics, metabolomics, functional foods, food quality

Food quality, as well as food production and treatment are important challenges in the actual society, increasingly interested in ensuring the quality of food and its beneficial effects for health. In general foods are complex systems, in fact “living systems”, endowed with a great complexity. So to deepen the multiple processes and reactions that cross-linked in food, from its production, transformation and conservation, to consumption, as well as to identify processes of adulteration and provenance confirmation, powerful instrumental tools are necessary, which combine the simultaneous study of metal-containing biomolecules, metabolites and proteins. In this way, the use of metal speciation approaches, metallomics and metabolomics represent the “new frontier” of research in this field.

Most of the approaches proposed for this purpose are based on the use of elemental and molecular mass spectrometry (ICP-MS and QTOF-MS) generally coupled to any chromatographic system (GC and HPLC).

Olive oil authentication Direct infusion electrospray ionization (ESI) and the

atmospheric pressure photospray ionization source (APPI), coupled to quadrupole time-of-flight (QqTOF), have been applied to control olive oil adulteration. These techniques are very fast (approximately 1 min per sample) and have high discrimination power to elucidate key components in edible oils: olive, hazelnut, sunflower and corn), which allows detect adulterations of olive oil [1].

Metal-containing biomolecules in pine nuts Pine nuts (Pinus pinea) from different geographical

origin in Spain and Portugal have been investigated using size-exclusion chromatography (SEC) with UV detection and inductively coupled plasma mass spectrometry (ICP-

MS). Two columns were used covering the molecular weigh range from < 10 to 70 kDa. that allowed the discrimination of the studied samples. Data reveal that the most differential UV-profile with low molecular weight (LMW) metal-biomolecules size distribution patterns of Mn, Zn, Ni and Cu allows discrimination of pine nut samples according to their provenance [2].

Se-enriched microalgae as functional food A metallomic analytical approach based in the

coupling high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS), which uses two chromatographic switched columns (C-18 and chiral columns) with ICP-MS detection, has been applied to characterize the different Se metabolites, including chiral forms, in both the algae and culture medium. The results reveal that selenate present in the culture is biotransformed in selenocystine (SeCys), selenomethyl-selenocysteine (SeMeSeCys), and mainly selenomethionine (SeMet) by the algae. What opens the doors to the use of this microalgae as a functional food of Se [3].

Metabolomic study of strawberries under different post-harvest controlled atmosphere treatments

Untargeted metabolomic profiling analysis based on gas chromatography-mass spectrometry (GC-MS) was employed to compare control and treated strawberries samples for the identification of altered metabolites caused by the treatment consisting of lower O2 and high CO2 atmosphere that reducing respiration rates and delaying the ripening process. Metabolomic analysis revealed significant differences for fruits under 20 % CO2 treatment (48h at 0ºC) mainly related with several metabolites including sugars (fructose, glucose) and organic acids (malic acid, phosphoric acid) among others.

References [1] J.L. Gomez-Ariza, A. Arias, T. Garcia-Barrera, R. Beltran, Talanta 70 (2006) 859. [2] J.L. Gomez-Ariza, A. Arias-Borrego, T. Garcia-Barrera, J Chromatog A 1121 (2006) 191 [3] V. Gomez-Jacinto, T. Garcia-Barrera, I. Garbayo, C. Vilchez, J.L. Gomez-Ariza, Pure Appl. Chem. 84(2012) 269.

Acknowledgement Projects CTM2015-67902-C2-1-P from the Spanish Ministry of Economy and Competitiveness (MINECO) and P12-FQM-

0442 from Regional Ministry of Economy, Innovation, Science and Employment (Andalusian Government, Spain). S. Ramirez-Acosta to Ministry of Economy and Competitiveness for PhD scholarships (BES-2016-076364). Authors are grateful to FEDER (European Community) for financial support, Grant UNHU13-1E-1611 and UNHU15-CE-3140.

17

Synthesis and characterization of smart hydrogel systems

Sabine Hild

Institute of Polymer Science, Johannes Kepler University Linz

Hydrogels are aqueous microgels that have found their way in a considerable number of applications but often with the disadvantage of their poor mechanical properties. For example, to apply such polymers for flexible electronics they should be transparent, easy to manufacture and expandable, beyond that they should be able to combined with the encapsulated electronics. Double crosslinked microgels (DX microgels) are shown to achieve these properties. Since flexible electronics is often used in biomedical sensors and devices biocompatibility has become an important issue. Thus, the focus of our research is on to prepare and characterize DX microgels of mainly biological and nontoxic precursors based on commonly used and cheap materials like gelatine or chitosan. To reinforce these materials specific “biofriendly” precursors are needed,

such as polyethylengylcol or acrylate polymers which are excellent for crosslinking via photopolymerization.

Confocal Raman microscopy (CRM) is a suitable method for the chemical characterization on the microscopic scale e.g. direct observation of crosslinking processes. The combination of CRM with rheometry enables to follow the crosslinking process by detecting variation of chemical and mechanical properties. DX microgels with improved adhesive properties are of importance for application because they will be combined with various materials of the analytical or electronic devices. A new approach for though bonding of hydrogels to other materials is to use cyan acrylate glues. The characterization of interfaces by CRM for different material combinations is reported.

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18

Lipid Driven Nanodomains Are Fluid

R. Šachl, M, Amaro, A. Koukalová, L.Veľas, and M. Hof

J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova

3, 18223 Prague 8, Czech Republic

It is a fundamental question whether sphingomyelin (SM)- and cholesterol (Chol)- driven nanodomains exist in cells and in model membranes. Studies on model membranes revealed SM and Chol driven micrometer-sized liquid-ordered domains. Although the existence of such microdomains has not been proven for the plasma membrane, such lipid mixtures have been used as a model system for ‘rafts’. On the other hand, super resolution results indicate that the plasma membrane might organize into nanocompartments. However, due to the limited resolution of those techniques their unambiguous characterization is still missing. In this lecture, a combination of Förster resonance energy transfer and Monte Carlo simulations (MC-FRET) [1]

identifies directly 10 nm large nanodomains in liquid-disordered model membranes composed of lipid mixtures containing SM and Chol [2]. Our MC-FRET approach can determine the sizes and concentrations of nanodomains down to 2 nm and enables studying the nanodomain inter-leaflet coupling. Combining MC-FRET with solid-state wide-line and high resolution magic angle spinning NMR as well as with fluorescence correlation spectroscopy [3] we demonstrate that these nanodomains containing hundreds of lipid molecules are fluid [2]. Addition of GM1 ganglioside, a molecule which forms already fluid 6 nm sized clusters in fluid phosphatidylcholine bilayers [4,5], leads to growth of those nanodomains while preserving the fluidity [5].

[1] R. Šachl et al. Biophys. J., 101, L60-L62, 2011 [2] A. Koukalová et al. Scientific Rep. vol. 7 p. 5460, 2017. [3] R. Šachl et al. J. Phys. D 49 189601, 2016 [4] R. Šachl et al. BBA- Mol. Cell Res. 1853, 850-857, 2015. [5] M. Amaro et al. Angew. Chem. vol. 55 p. 9411-9415, 2016.

19

PHA - A Biodegradable Plastic To Solve Society Problems?

Ines Fritz 1

1 Ines Fritz; University of Natural Resources and Life Sciences; Department IFA-Tulln; Konrad Lorenz

Str. 20; A-3430 Tulln; [email protected]

Keywords: PHA, biodegradable plastic, litter, food packaging, cyanobacteria

While plastics are agreed to be the solution to many problems of mankind, the drawbacks of cheaply produced consumer and convenience products didn't show off, until late. The discussion isn't only about drifting plastic in the oceans and micro-plastic particles in our food, it is a question of resources - of sustainable resources - to be precise.

PHA (poly-hydroxyalcanoates) are one class of biobased polymers with the potential to replace some types of conventional plastics. At least in the future. PHA are native storage products of many bacteria, which can efficiently grow on sugar, can be set up to utilise waste streams or can be isolated from photo-autotrophically

growing cyanobacteria. With a closer look on these processes, advantages and disadvantages of each of them become apparent. While to use of agricultural resources for purposes other than food and feed arises ethical conflicts, the utilisation of waste streams has to deal with fluctuating composition and impurities. Finally, photo-autotrophic production turns out to be slow and needs large reactor volumes. However, there is one aspect all of them have in common: a much too high price of the polymer.

What can biobased and biodegradable polymers be good for to overcome the economic disadvantage - or, more specifically - is there a future for PHA's?

Acknowledgement Parts of the presented data were generated within the research project CO2USE, funded by the Austrian Research

Association FFG under the project number 834422.

20

Photopolymerization: From Biomaterials to 3D Printing

Robert Liska

Institute of Applied Synthetic Chemistry,

Vienna University of Technology, Getreidemarkt 9/163/MC, 1060 Vienna, Austria,

[email protected]

UV curing of photopolymerizable formulations has been used for more than a half century for protective and decorative coatings of paper, wood, metals or plastics. Advantages can for sure been found in the high curing speed that allows the conversion of typically (meth)acrylate-based monomers within the fraction of a second. Furthermore, a large variety of monomers is commercially available so that the mechanical properties and other polymer characteristics can be easily tuned.

In the last decade there has been a strong demand for the curing of bulk materials. If one wants to have arbitrarily shaped 3D cellular structures, additive manufacturing technology (AMT), also called Rapid Prototyping, is the method of choice. Different setups are commercially available that allow the printing of photopolymerizable formulations from a simple CAD model. Laser or DLP (Digital light processing) based systems fabricate polymer parts with a feature resolution of about 10 µm. In recent days not only

prototypes are of interest, also small number of individual parts that can be used in the automotive industry or for medical applications are important. Especially in the latter case monomers and polymers with low toxicity should be used. Vinylcarbonates represent a new and interesting class of photopolymers with exceptionally low cytotoxicity and suitable photoreactivity. Degradation can be easily tuned giving non-toxic low molecular polyvinyl alcohol as degradation product and various non-toxic alcohols such as glycerol or polyethylene glycol. In vivo experiments demonstrated excellent biocompatibility.

Two photon photopolymerization (TPP) is another rapid prototyping technique that allows a real 3D writing process with feature resolutions of about 200 nm. Using suitable monomers and photoinitiators we were able to write with a femtosecond pulsed laser in the presence of living cells without harming them.

21

Biodegradable Polymer Materials: Properties, Applications, and

Environmental Fate

Marek Koutný1, Jana Šerá1, Jan Salač1

1 Tomas Bata University in Zlín, Faculty of technology, Department of environmental protection

engineering, Vavrečkova 275, 76001 Zlín, [email protected]

Keywords: biodegradable polymer materials, polyesters, plastic waste, soil, composting

Plastic materials, in this context especially plastic packaging materials, became a part of our everyday life and greatly improved e.g. food hygiene, shelf life and the overall culture of the food supply chains and retail. On the other hand plastic waste amount and its accumulation reached the scale when it is regarded as alarming by both the public and regulatory bodies. The only solution to this problem is the necessity to constantly build and improve the system of plastic waste separated collection and recycling. Such system has to be able to distinguish different polymer materials to create sufficiently well-defined and economically viable streams of the recycled materials.

Fig. 1. Erosion after bacterial biodegradation of the aliphatic-aromatic co-polyester based material

In some particular applications it seems useful to replace standard polymer materials with the biodegradable alternatives. There are several such basic polymers available which differ in their properties important for their processing and application but also in the way of their environmental degradation. Nowadays all these materials are polyesters of various origins and properties. The design of the final polymer materials can be greatly improved by blending the individual polymers and biodegradable fillers eventually and employing other types of additives like nucleation agents, plasticizers, chain extenders etc. It seems that with the help of these approaches it is possible to finally overcome relatively poor properties of the raw biodegradable polyesters and turn them into useful materials.

Above outlined modifications can also deeply influence the biodegradability of the materials which then must be evaluated but they can also be employed to control the rate of the biodegradation in different conditions.

It is thus very important to develop a given material for a particular application reflecting all stages of its life cycle from its processing and application to its biodegradation.

The ultimate goal of this endeavor is the development of materials with programmed properties during their life cycle.

22

Improved Nitrogen Fertilisers Utilising Humic Material Blends

Biplob K. Saha1, Michael T. Rose2, Vanessa Wong3, Timothy R. Cavagnaro4 and Antonio F. Patti1*

1 School of Chemistry, Monash University, Clayton, Victoria, 3800, Australia 2 NSW Department of Primary Industries, Wollongbar Primary Industries Institute, Wollongbar,

NSW 2477, Australia 3 School of Earth, Atmosphere & Environment, Monash University, Clayton, Victoria, 3800, Australia 4 School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, South Australia,

5064, Australia, [email protected]

Keywords: Brown coal-urea blend, biomass yield, N uptake, fertiliser N use efficiency, soil health

Increasing crop yield combined with minimum application of nitrogenous fertilisers is becoming more important due to detrimental effects of excess N in the environment. Addition of humic rich-brown coal as an organic amendment to urea, and application to soil, can alter nitrogen (N) cycling and availability to crops. However, the effect of brown coal-urea (BCU) blends on the biomass yield and N uptake by plant needs to be studied. Therefore, a glasshouse pot trial was conducted to assess the effects of BCU blends on the growth, biomass yield and N uptake by silver beet. Blending of urea with brown coal showed a promising impact on the behavior of N fertiliser in the soil system. Compared to urea, BCU blends increased biomass yield by 27% and 23% in a neutral (pH 7.24) and acid (pH 5.4) soil,

respectively. In addition, incorporation of BCU blends to soil generally suppressed N2O emissions by 29% compared to urea. Application of BCU blends in soil maintained significantly higher amounts of potentially mineralisable N in soil compared to urea application only. Moreover, addition of BCU blends increased the N uptake by silver beet and organic carbon content of soil. The blends with higher brown coal had higher biomass yield, better N uptake and maintained higher mineral N in soil compared to the blends with lower brown coal. The overall results suggest that blending of urea with brown coal can significantly increase N availability and its uptake by silver beet. As a result a better crop yield can be obtained and at an increased N use efficiency, compared with urea alone.

23

Nanostructure of Cementitious Products: A MAS-NMR Approach

Angel Palomo1, Ana Fernandez-Jimenez1

1 Instituto Eduardo Torroja (IETcc), CSIC, C/Serrano Galvache 4, 28033 Madrid, Spain,

[email protected]

Keywords: MAS-NMR, blended cement, hybrid alkaline cement

A This presentation focuses on the application of NMR to the

27Al and

29Si nuclei of the main components

of the most prevalent construction binders such as portland cement and other aluminosilicate materials used as additions in OPC or to manufacture alternative cements. Prior to citing examples of applications of the technique, a brief reminder about the today’s cement research, obviously geared to the development of environmentally sustainable binders, may be in order.

The mass production of portland cement raises certain energy and environmental issues, for it calls for

temperatures of up to 1400 C-1500 ºC, entails the extraction of raw materials with the concomitant destruction of natural quarries and emits GHGs such as CO2 and NOx. The 0.8 tonnes of CO2 emitted per tonne of cement manufactured contribute substantially to global air pollution (the cement industry accounts for 7 % to 8 % of worldwide CO2 emissions).

One of the solutions to these problems, widely accepted today by the scientific community, is to replace clinker with supplementary cementitious materials (SCMs), consisting in minerals such as natural pozzolans or industrial by-products such as blast furnace slag or fly ash. The resulting products are known as blended cements. Building codes the world over specify both the type and maximum amount of additions that cements can bear. The SCMs added to clinker are in general Si- and Al-higher and Ca-lower than clinker itself. The C-S-H gels forming in the presence of SCMs have a smaller Ca content than found in pure OPC and may also contain aluminium in their structure. An understanding of the amount of Al, its position in the C-S-H gel and the parameters that favour its uptake is important, for the presence of the element may affect the cohesion and durability of the material. Aluminium uptake in C-S-H gel gives rise to what are called C-(A)-S-H or C-A-S-H (CaO-Al2O3-H2O) gels, depending on the aluminium content. The presence of aluminium in the C-S-H gel structure may favour the formation of inter-silicate chains and the conversion of a linear (1D) to a two-dimensional (2D) or crosslinked structure.

Another possible, more innovative, approach to the overall problem facing the cement industry consists in developing more economical and eco-friendly (lower CO2 emissions, industrial by-product valorisation) alternatives to ordinary portland cements that exhibit comparable or even enhanced characteristics and

properties. A series of binders generically known as ‘alkaline cements’ constitute one such option.

Alkaline cements are cementitious materials formed as the result of the dissolution of amorphous or vitreous natural materials or industrial waste in an alkaline medium.

So-called hybrid or blended alkaline cements are characterised by low clinker and high SCM contents, along with a small proportion of an alkaline activator to favour initial strength development. These cements are the outcome of combining the existing knowledge of OPC and alkaline cements. The inference drawn from the foregoing is that an understanding of the compatibility between the gels described is of utmost importance. In this presentation a number of examples of NMR-based compatibility studies (conducted on synthetic cementitious gels: C-S-H, C-A-S-H and N-A-S-H, and gels from real samples) will be discussed.

NMR has been instrumental over the last 30 years in chemistry of cement research, in particular as regards the composition and structure of the aforementioned cementitious gels (C-S-H, C-A-S-H and N-A-S-H). Given their amorphous nature, these substances are very difficult to characterise using XRD. One of the earliest studies in the literature on the application of NMR to cement, a paper on tobermorite structure, dates from 1974 (Sixth ICCC, held at Moscow). Since then, the number of studies using this technique to characterise binders has risen exponentially.

Research has been so prolific since 2000 that it is difficult to highlight any studies in particular. Nonetheless, significant work has been conducted recently on the changes in C-S-H gel structure and composition due to the uptake of aluminium, nanosilica, alkaline ions and so on, as well as on the application of NMR to the study of the structure and composition of both the precursors and the reaction products forming in the new binders.

Lastly, whilst this technique has driven progress in the understanding of the effect of many variables on cement structure and composition, a number of unknowns have yet to be unravelled. NMR may play a very significant future role in the acquisition of a detailed understanding of the composition and structure of both precursors and the hydration products formed (gels in particular) in the development of more eco-friendly cements, such as mentioned above: blended cements, sulfobelite cements, alkaline cements and blended or hybrid alkaline cements.

24

PHA Workshop

25

Extremophiles – platform strains for sustainable production of

polyhydroxyalkanoates

Stanislav Obruca1, Dan Kucera1, Eva Slaninova1, Iva Pernicova1, Petr Sedlacek1, Filip Mravec1, Ivana

Marova1, Ota Samek2, Ladislav Krzyzanek2, Martin Vanek1, Adriana Kovalcik1, Lucie Mullerova1, Aneta

Chytilova1, Ivana Novackova1, Olga Kratochvilova1, Jana Nebesarova3

1 Faculty of Chemistry, Brno University of Technology, Purkynova 118, 612 00 Brno, Czech Republic 2 Institute of Scientific Instruments, Academy of Sciences of The Czech Republic, Vvi, Kralovopolska

147, 612 64 Brno, Czech Republic. 3 Biology Centre, The Czech Academy of Sciences, v.v.i., Branisovska 31, 370 05 Ceske Budejovice,

Czech Republic.

Keywords: polyhydroxyalkanoates; extremophiles; bio-refinery; waste valorization

Polyhydroxyalkanoates (PHA) are microbial polyesters which are accumulated as storage compounds by numerous prokaryotes in form of intracellular granules. In addition to their primarily function, PHA enhances robustness and stress resistance of bacteria against various stress factors such as high temperature or oxidative pressure, freezing, UV-irradiation or osmotic up- and down-shock [1].

Apart from their biological function, PHA has been for decades attracting attention as completely biodegradable and biocompatible polymers which can be produced from renewable resources including waste streams of agriculture and industry. Therefore, these materials are generally considered being “green” alternative to petrochemical polymers. Despite their ecological nature and great application potential, commercial production of PHA at industrial scale is scarce which is predominantly caused by the high production cost associated with traditional industrial biotechnologies such as cost of carbon substrate, sterilization demands and low efficiency of batch or fed-batch cultivation mode.

Therefore, the solution of above mentioned problems could be employment of extremophiles as PHA production strains. Extremophiles are naturally robust microorganisms which are capable to survive and prosper under conditions which eliminate potential risk of contamination. Therefore, sterilization expenses are minimized or even completely omitted and the process can be operated in more efficient continuous mode. Nevertheless, it is essential to collect critical amount of knowledge in the field of PHA synthesis by extermophillic bacteria. In this context we have recently screened various halophiles for their PHA production capabilities, the strains were evaluated based on analysis of their genotype as well as phenotype. Among all the tested bacteria, we have identified halophilic bacterium

Halomonas halophila as very promising PHA producing strain. This strain could, due to its superior capability of utilization of lignocelluse and other waste/inexpensive substrates accompanied by great PHA accumulation capacity, be considered being very strong candidate for industrial production of PHA. Moreover, it should be noted that molecular weight of the polymer produced by H. halophila can be adjusted by controlling salinity of the cultivation media [2]. It should be noted that PHA accumulation capability is very common feature among halophiles which indicate that PHA could be involved in adaptation to high salinity environments.

Figure 1: Transmission Electron Microscopy analysis of

PHA granules containing halophilic bacteria a) Halomonas halophila b) Halomonas neptunia

Apart from halophiles, we have also been working on

isolation of thermophilic PHA producers. We have employed dynamic feeding strategy to enrich thermophilic activated sludge in PHA producing strains, further, potential PHA producers were isolated based on their phenotype (positive Nile Red staining test on Petri dishes) as well as genotype (PCR proof of presence of phaC gene encoding for PHA synthase). Promising candidates were further identified by 16S rDNA sequencing.

References [1] S. Obruca, et al., Biotechnology Advances 36 (2018) 856. [2] D. Kucera et al., Bioresource Technology 256 (2018) 552.

26

Biological valorization strategy for converting spent coffee grounds

into biopolymers and chemicals

Adriana Kovalcik1, Dan Kucera1,2, Stanislav Obruca1,2, Helena Hudeckova1,2, Ivana Marova1,2

1 Department of Food Chemistry and Biotechnology, Faculty of Chemistry, Brno University of

Technology, Purkynova 118, 612 00 Brno, Czech Republic

2 Materials Research Centre, Faculty of Chemistry, Brno University of Technology, Purkynova 118,

612 00 Brno, Czech Republic

Keywords: Biopolymers, waste material, antioxidants, antibacterial agents, valorization

Coffee is the second largest traded commodity in the world. More than 6 million tons of spent coffee grounds (SCG) per year are generating worldwide as a solid residue after beverage preparation or instant coffee production [1]. In the time when we should save carbon sources and use the carbon only we have to, SCG belong to valuable renewable sources of carbon.

This work suggests a biological valorization strategy for converting of SCG into polyhydroxyalkanoates (PHA), lactic acid, carotenoids, antioxidants, antimicrobial agents, and filler for polymers [2 - 4]. For the suggested approach, the fractionation of SCG is a crucial step. For the biotechnological production of PHA, oil derived from SCG after extraction with n-hexane as well as fermentable sugar derived from SCG through hydrolysis have been used. SCG hydrolysates have been detoxified through an adsorption strategy by using Amberlite XAD4. Amberlite XAD4 is a non-ionic crosslinked polymer, which adsorptive properties are connected with its macroreticular structure, high surface area and the aromatic nature of its surface. XAD4 have a capacity for the adsorption of organic substances from aqueous systems. The compounds trapped on Amberlite XAD4 showed high antioxidative and antimicrobial activity and can be used as bioactive compounds with the use in pharmacy, food and polymer industry. The rest solid material after neutralization and composting can be used as fertilizer or after modification as filler for polymers.

In conclusion, it can be said that nowadays, when many concerns about consequences of depletion of natural resources and the rapid changing of the climate have arisen, the broad availability of SCG should be accepted and utilized wisely as “value-added product” [5].

References

[1] A.T. Getachew, Y. J. Cho, B.S. Chun, B. S. Int. J. Biol. Macromol. 109 2018), 711.

[2] S. Obruca, P. Benesova, D. Kucera, S. Petrik, I. Marova. New Biotechnol. 32 (2015), 569. [3] H. Hudeckova, M. Neureiter, S. Obruca, S. Fruehauf, I. Marova. Lett. Apl. Microbiol. 66 (2018) 306. [4] A. Kovalcik, P. Matouskova, D. Kucera, S. Obruca, I. Marova. In: EUBCE 2018, 26

th European Biomass

Conference & Exhibition, 14 – 17 May 2018, Copenhagen, Denmark, Book of Abstracts Summaries, p. 20 [5] A. Kovalcik, S. Obruca, I. Marova. Food Bioprod. Process. (2018) In Press.

Acknowledgement This work was funded through the project SoMoPro

(project No. 6SA18032). This project has received funding

from the European Union’s Horizon 2020 research and

innovation programme under the Marie Skłodowska-

Curie, and it is co-financed by the South Moravian Region

under grant agreement No. 665860. This work was also

supported through the project “Materials Research Centre

at FCH BUT—Sustainability and Development”

Nr.LO1211 of the Ministry of Education, Youth and Sport

of the Czech Republic.

Note: Authors confirm that the content of this work

reflects only the author’s view and that the EU is not

responsible for any use that may be made of the

information it contains.

27

Monitoring of biotechnological production of microbial substances

using Raman spectroscopy

Ota Samek1, Stanislav Obruča2,3, Jan Ježek1, Silva Bernatová1, Zdeněk Pilát1, Andrea Hároniková2,3,

Ivana Márová2,3, Petr Sedláček2,3, Dominika Gonová2, Martin Šiler1, Pavel Zemánek1

1 Institute of Scientific Instruments of the Czech Academy of Sciences, v.v.i., Brno, Czech Republic;

[email protected] 2 Material Research Centre, Brno University of Technology, Brno, Czech Republic 3 Institute of Food Science and Biotechnology, Brno University of Technology, Brno, Czech Republic

Keywords: Raman spectroscopy, microorganisms, biotechnology

The main goal of our project is the development of specialized instrumentation and methodology to monitor microorganisms in order to optimize cultivation processes for biotechnological applications using Raman spectroscopy. Raman spectroscopy offers a powerful alternative analytical method for the detection and identification of different substances in biological samples, such as bacteria, yeast and microfungi.

Biomass of different microorganisms has been studied using Raman spectroscopy due to its potential applications in the field of biofuel generation, food industry and biotechnological applications. In order to utilize biomass for efficient industrial/biotechnological production, the optimal cultivation parameters have to be determined which in turn leads to high production of desired substances such as oil, carotenoids, polymers, and pigments in the selected microbial samples.

Therefore, we focused on different cultivation conditions and their influence on microorganisms growth and metabolic changes. The attention was given to the different oil, pigment or polymer producing yeast strains and various bacteria which accumulate biodegradable polyesters (PHB) and polymers to exploit their potential applications in the area of biotechnology and chemical engineering. Namely, we investigated following microorganisms - Aureobasidium pullulans (producer of pullulan), Cupriavidus necator H16 (PHB), E. Coli (Cyanophycin) and Metchnikowia (oil and Pulcherrimin).

In order to utilize selected microorganisms for

efficient production of desired substances, the influence of different cultivation parameters on cells can be monitored using our dedicated instrumentation (Figure 1). In our preliminary experiments we found that if the yeast is cultured under the right conditions up to 40

percent of the cell weight can be oil. In case of polyesters producing bacteria content of PHB can be as high as 90 percent for selected bacterial strains [1].

Figure 1: Spectral map plotted using Raman line intensities for monitoring of unsaturated oil in the cells during 14 collection days (vertical line). The map nicely shows (qualitatively) increasing production of unsaturated oil within the cells with maximum at the last day.

The whole procedure - from sample preparation to advanced chemometric methods - can take several minutes. Thus, Raman spectroscopy proved to be a very efficient tool for the rapid quantitative/qualitative analyses of various substances produced by microorganisms.

We believe that our study will be of significant

assistance to research groups being involved in the area of biotechnology, microbiology, chemical engineering and food processing.

References [1] O. Samek, S. Obruča, M. Šiler, P. Sedláček, P. Benešová, D. Kučera, I. Márová, J. Ježek, S. Bernatová, P. Zemánek,

Sensors 16 (2016) 1808.

Acknowledgement The research was supported by the Technology Agency of the Czech Republic (project TG03010046-04), MEYS CR

(LO1212), its infrastructure by MEYS CR and EC(CZ.1.05/2.1.00/01.0017) and by CAS (RVO:68081731).

28

Environmental Chemistry and Technology

29

The photocatalytic decomposition of methanol over photocatalyst

based on the TiO2

Abouali galedari, N.a, Dubnová, L. b, Matějová, L. a, Reli, M. a, Drobná H. b, Čapek, L.b, Kočí, K. a

a Institute of Environmental Technology, VŠB-Technical University of Ostrava, 17. listopadu

15/2172, 708 33 Ostrava, Czech Republic b Faculty of Chemical Technology, University of Pardubice, Studentská 573, 532 10 Pardubice, Czech

Republic

Keywords: Hydrogen production, Photocatalysis, TiO2

Hydrogen is proved to be the fuel of the future because it is the most plentiful element in the universe and due to its non-polluting energetic conversion. Using photoctatalytic active material such as TiO2 is a promising step for solar hydrogen production. It has been reported that hydrogen production is much higher in case of water-methanol mixture due to the fact that methanol has a high hydrogen/carbon ratio and also it could be noted that methanol can be obtained either from fossil resources or from biomass.

TiO2 has attracted extensive attention for photocatalytic application because of its high efficiency,

high stability, low toxicity, and low price. However, the wide band gap (3.2 eV) and the rapid recombination of electron–hole pairs of TiO2 reduce its photocatalytic efficiency. Doping of TiO2 with lanthanide ions is a promising step toward altering the photocatalytic efficiency of TiO2. It can reduce agglomeration of TiO2 particles in the aqueous medium, inhibit electron-hole recombination by acting as an electron trapper, and also it can increase the temperature of the anatase to rutile transformation.

Acknowledgement: The financial support of the Grant Agency of the Czech Republic ((projects No. 14-23274S and 14-35327J), “National

Feasibility Program I”, project LO1208 “TEWEP” from Ministry of Education, Youth and Sports of the Czech Republic and SP2015/125 are acknowledged.

30

Urban aerosol: metals as starters of cellular stress?

Hana Barboříková1, Pavel Mikuška2, Jozef Krajčovič1

1 Brno University of Technology, Faculty of Chemistry, Chemistry and Technology of Environmental

Protection, Purkyňova 118, 61200 Brno, Czech Republic, [email protected] 2 Institute of Analytical Chemistry of Czech Academy of Sciences, Department of Environmental

Analytical Chemistry, Veveří 967/97, 60200 Brno, Czech Republic

Keywords: aerosol, oxidative potential, metal, dithiothreitol

Atmospheric particulate matter (PM) affects our environment especially human health because it contains many toxic chemical substances. Some of them, i.e. PAHs and toxic metals may cause serious disease [1]. Transition metals generate reactive oxygen species (ROS) which are reactive molecules and free radicals derived from molecular oxygen. ROS concentrations exceeding the antioxidant capacity to neutralize them, lead to health damage through the oxidation of other cellular components and therefore oxidation potential can be an indicator of potential health effects [2].

The purpose of this study is to determine a total content and a soluble fraction of Cu, Pb, Zn, Mn, Fe, Cd, Cr, Ni, V, Co and also the contribution of metals soluble in pulmonary fluids to a total oxidative potential of particulate matter. Aerosol samples (size fractions PM2.5 and PM1) are collected in Brno, Czech Republic for two weeks in four different seasons. Each sample is collected for 48 h on a nitrocellulose filter (150 mm, 3 µm pores, Sartorius) using a high-volume sampler (DHA-80 or DH-77, Digitel). Filters with collected aerosols are digested in HNO3 and the total content of selected metals in samples is determined by ICP. The soluble fraction of metals is determined by means of extraction of filters in water, a Gamble´s solution and a solution based on dipalmitoyl phosphatidyl choline, named as Simulated Alveoli Fluids (SAF) and the content of metals in extracts is determined by means of AAS [3].

Oxidative activity of two size fractions of particulate matter and selected metals is determined using dithiothreitol (DTT) assay. It was discovered that except several quinones DTT is also oxidized by some of the transition metals [4]. While the metals are less reactive in the DTT compared to the quinones, the concentration of soluble fraction of metals in particulate matter is usually higher than those of quinones.

PM

O2 O2

SH

S

OH

OH

SH

SH

OH

OH

PM

O2 O2

S

S

OH

OH

SH

S

OH

OH

Figure 1: Dithiothreitol oxidation to its disulphide form superoxide anion

Oxidative potential of individual metals is compared first using standard solutions of the metals dissolved in water, Gamble´s solution and SAF.

Figure 2: Example of slopes evaluated for standard copper solution. The rate of DTT loss is determined as the slope of sample regression line minus the blank slope.

References [1] WHO, THE PEP, UNECE, Transport-related health effects with a particular focus on children, 2004. [2] D. Chirizzi, D. Cesari, M. R. Guascito, A. Dinoi, L. Giotta, A. Donateo, Atmospheric Environment, 163 (2017) 1-8 [3] P. Coufalík, P. Mikuška, T. Matoušek, Z. Večeřa, Atmospheric Environment, 140 (2016) 469-475 [4] J. G. Charrier, C. Anastasio, Atmospheric Chemistry and Physics 12 (2012) 19

Acknowledgement This work was supported by Grant Agency of the Czech Republic under grant No. P503/12/G147. HB thanks to project no. FCH-S18-5331.

31

Toxicity of Some Nitramines

Karel Bednařík1, Papírek Jan2

1 Brno University of Technology, Faculty of chemistry, Institute of Chemistry and Technology of

Environmental Protection, Purkyňova 118, 612 00 Brno, [email protected]

2 Brno University of Technology, Faculty of chemistry

Keywords: nitramine, toxicity, Lemna Minor

The toxicity of two nitramines which are used as very effective explosives in special utilization was tested in this work. Tested compounds were 3,7-dinitro- −1,3,5,7-tetraaza-bicyclo[3.3.1]nonane (DPT) and 3,7-dinitroso-1,3,5,7-tetraazabicyclo[3.3.1]nonane (DNPT)

Figure 1: Structure formulas of tested compounds

because their toxicity was not tested previously and because other similarly explosives are very arduous to preparation. Lemna Minor was used as testing plant. The tested compounds were prepared by procedures given in literature [1] for DPT and [2] for DNTP. The test plant was exposed to various concentrations of the test compounds so as to determine the IC50 (mg.l

-1) values.

The tested compounds were diluted in nutrient solution with addition of 2% of acetone for their better solubility, which did not affect to plant growth, as was demonstrated by a preliminary test.

After a preliminary test at a wide concentration range, a limited range was chosen to determine the desired values.

The followed mixtures were used to preparation of nutrient solutions: 20 ml of mixture 17.5 g of sodium

nitrate; 4.5 g of monopotassium phosphate and 0.63 g of dipotassium phosphate in 1000 ml of water, 20 ml solution of 5.0 g magnesium sulfate heptahydrat in 1000 ml of water, 20 ml solution of 14.75 g calcium nitrate tetrahydrate in 1000 ml of water and 1 ml of solutions of 120 mg of boric acid,, 180 mg of zinc sulfate heptahydrate, 44.0 mg of sodium molybdate dihydrate, 180.0 mg of manganese(II) chloride tetrahydrate, 0.76 g of iron(III) chloride hexahydrate and 1.50 g of ethylenediaminetetraacetic acid disodium salt dihydrate, each in 1000 ml of water. This mixture was suplement to 1000 ml by water.

The solutions of both compounds from the orientative and final test were poured in 150 ml beakers. To each of the beakers, including controls was transferred nine teaspoon leaves and the beakers were covered with Petri dishes.

The beakers were placed in a laboratory with a constant temperature of 24-25 °C under artificial lighting, where they were continuously for seven days.

Every twenty four hours, the number of fluff leaves and their possible chlorosis (yellowish tissue) or necrosis (white blown tissue) were recorded.

Based on these tests, the following results were obtained: The value of IC50 for DPT was set at 18.4 mg.l

-1,

for DNTP then at 65.0 mg.l-1

. Based on these results, we can conclude that both substances can be classified as harmful to aquatic organisms (IC50 are from 10 to 100 mg.l

-1, risk phrase R52).

References

[1] Xiao-BING, L. I. U. and MING, L. U.: Synthesis of 3,7-Dinitro-1,3,5,7-tetraazabicyclo-[3,3,1]nonane Using Task-Specific Ionic Liquids as Recoverable Catalysts. E-Journal of Chemistry [online]. 8(1), 97-100, (2011) [cit. 2017-05-06]. DOI: 10.1155/2011/573540. ISSN 0973-4945. Available from: http://www.hindawi.com/journals/jchem/2011/573540/

[2] BACHMANN, W. E. and DENO, N. C.: The Nitrosation of Hexamethylenetetramine and Related Compounds 1., Journal of the American Chemical Society [online]. 73(6), 2777-2779, (1951) [cit. 2017-05-05]. DOI: 10.1021/ja01150a102. ISSN 0002-7863. Available from: http://pubs.acs.org/doi/abs/10.1021/ja01150a102

N

N

NN NOON

DNTP

N

N

NN NO2O2N

DTP

32

Application of Statistical Methods for Assessment of Soil Pollution

Helena Doležalová Weissmannová 1, Silvie Mihočová 1, Petr Chovanec 1, Jan Brzobohatý 1

1 Brno University of Technology, Faculty of Chemistry, Purkyňova 118, Brno, 612 00,

[email protected]

Keywords: heavy metals, soil pollution, indices, multivariate statistical methods

The soil pollution by heavy metals is one of the most important environmental problems. The increasing trend of heavy metal contamination in environment results to a growing global risk to human and environmental health; the soil pollution by toxic and hazardous substances causes to global degradation or loss of some soil functions. Anthropogenic pollutants in air, soil and water result in the most striking negative impact of anthropogenic activity on the terrestrial and aquatic ecosystems. The localization of heavy metal pollution sources due to industrialization and urbanization is important for solving many environmental problems. The main sources of pollution in urban and suburban areas are growing industries (chemistry, metallurgy, building and electronic industry, etc.), fuel combustion, and waste management and transport. Heavy metals originating from road transport accumulate in soil by dry and wet atmospheric depositions at some distance from the roads, and resulting in spatial gradient and spatial distribution of heavy metals in environment. The entry of heavy metals from anthropogenic activities generally includes: As, Cd, Cr (only Cr (VI) is toxic), Cu, Hg, Ni, Pb and Zn. Unfortunately, heavy metal pollution is irreversible.

The assessment of heavy metal pollution in soil include many methods, such as determine of heavy metal concentration in soils, use various pollution indices (single pollution indices, integrated pollution indices and ecological indices) and multivariate statistical analysis. The total concentration of heavy metal in soils is usually regarded as an indicator of urban environmental quality. Many various pollution indices calculated on the base of metal concentration, background metal concentration,

preindustrial concentration of metal, tolerable limits of metals, toxic response factor of individual metal and etc. calculating factors of metals allow assessment the contamination and classify the pollution levels [1-.5].

The Pearson's correlation, cluster analysis (CA) and principal component analysis (PCA) can be used as appropriate tools in environmental research and were used to identify the interrelationship among heavy metals and its various sources.

The contents of metals in soil samples from Ostrava and Brno were determined by method AAS. The total complex indices of soil pollution were also calculated on the base of single indices and they were divided into two groups: Integrated indices of pollution and indices of ecological risk. Besides, the descriptive statistics, the Pearson's correlation, CA, and PCA methods were used for source identification and origin of heavy metals in soils. The method PCA and DA were also used for divide of pollution indices on the base of interrelations.

References [1] H. Chen, Y., Teng, S., Lu, Y., Wang, J., Wang, Chemosphere 144 (2017) 1002. [2] D. Rosado, J. Usero, J. Morillo, Marine Pollution Bulletin 102 (2016) 65. [3] D.G. Streets, Z. Lu, L. Levin, A.F.H. Ter Schure, E.M. Sunderland, Science of The Total Environment 615 (2017) 131. [4] X. Wan, H. Dong, L. Feng, Z. Lin, Q. Luo, Chemosphere 178 (2017) 402. [5] Y. Hu, H. Chen, Environmental Pollution 214 (2016) 400.

Acknowledgement Authors thanks for support provided by the No. FCH-S-17-4766 “Assessment of pollution in environmental

compartments”.

33

Determination of PPD in Hair Dyes Collected from Local Markets in

El-Bieda city – Libya

Galal Elmanfe 1,3, Osama Khreit 2,3, Omukalthum Abduljalil3 and Enas S. Farag1

1 Chemistry department, Faculty of Science, Omar Al-Mukhtar University, El-Bieda, P.O 919, Libya 2 Pharmacology , Toxicology and Physiology department, Faculty of Veterinary, Omar Al-Mukhtar

University, El-Bieda, P.O 919, Libya. 3 Almukhtar Centre of Rerearch, Consaltation, Technique Services and training, , Omar Al-Mukhtar

University, El-Bieda, P.O 919, Libya. E-mail: [email protected]

Abstract

This study aims to determine the para-phenylenediamine (PPD) in hair dyes by High-Performance Liquid Chromatography (HPLC). In the presented study, ten hair dye samples were collected from local markets in El-Bieda - Libya. A rapid, simple and reliable method is developed and validated for the determination of PPD in hair dyes samples using 50% methanol solution as solvent. The method was validated over a wide linear range of 5 – 25 µg/mL with correlation coefficients being consistently greater than 0.997. The LOD and LOQ were 1.65 µg/ ml and 5.02 µg/ ml, respectively. Relative standard deviation (%R.S.D.) ranged between 0.07 and 1.92 %. The minimum PPD level was observed in Beauty Taoch (Blonde) sample (0.0855 % w/w), while Jourin Jsense Cosmetic (Black Blue) sample showed the highest PPD content (2.2526 % w/w). The HPLC measurments indicated that the results of PPD concentrations in Black colour samples were in the range of 0.3705 % - 2.2526 % w/w. Whereas its concentrations in anthor colour samples were in the range of 0.0855 % - 0.5936 % w/w. The level of PPD in Black colour samples were higher than other colour samples. The PPD content in all the samples analyzed in this study are well below the allowable limits set by the US Food and Drugs Administration.

Keywords: PPD ; Hair Dyes ; Methanol and HPLC.

Paraphenylenediamine (PPD) is a chemical substance that is widely used as a permanent hair dye [1]. It is primarily used as an ingredient of oxidative hair coloring products at a maximal concentration of 4.0%. In addition to hair dyes, PPD may also be found in fur or textile dyes, photographic developing agent and as an antioxidant in rubber compounds. Individuals may be occupationally exposed to PPD during its manufacture or use, and the exposure may occur through inhalation, skin and/or eye contact, and ingestion [2]. Currently, PPD is present in more than 1000 hair dye formulations marketed all over the world [3]. In our study, a rapid, simple and reliable method is developed, based on other methods recommended by other researchers with some modifications, in order to isolate and determine PPD in hair dyes and henna [4,5]. The method used is more rapid and simple compared with other methods [4,5]. The analyses were developed and validated by UV-Visible spectrophotmeter and HPLC.

Results for PPD in hair dye samples were in the range of 0.0855 % – 2.2526 % w/w. These results are shown in the table (1). The Concentrations of PPD in Black colour samples were higher than other colour samples.

Figure 1: Chromatograms of different concentrations of PPD by HPLC .

Table 1: Concentration of PPD in samples by HPLC n° Sapmle name PPD (% w/w) S1 Revlon - BLACK 1.45429 S2 JOURIN JSENSE COSMETICS - [BLACK BLUE 2.25259 S3 Bcllissima Color - [BLACK BLUE] 0.37052 S4 Bcllissima Color - Porphyry copper 0.54855 S5 Garnier color naturals - BLACK 1.13949 S6 MODA COLOR - BLONDE 0.59361 S7 Beauty Taoch - BLACK 1.10062 S8 Beauty Taoch - BLONDE 0.08553 S9 LADY COLOR - BURGUNDY 0.53073

S10 JUNGLE FEVER (JF) - BLACK NERO 0.37729

References [1] N. Puri, A. Puri, Nasza Dematologie (2013) 545. [2] Scientific Committee on Consumer Products (SCCP), 9th plenary meeting, Brussels, Belgium 10(10), (2006). [3] L.A. Stanley, J.A. Skare, E. Doyle, R. Powrie, D. D'Angelo, C.R. Elcombe, J Toxicol (2013) 147. [4] A. Al-Suwaidi, H. Ahmed, Int. J. Environ. Res. Public Health (2010) 1681. [5] C.H. Latha Saranya, B.M. Gurupadayya, K. Kinnera, J.C. Thejaswini, Turk J Pharm Sci. (2014) 295.

mailto:[email protected]

34

Anhydrous ethyl lactate synthesis by transesterification of

oligomeric lactic acid

Silvestr Figalla1, Jaroslav Petruj, Tereza Švestková

1 Department of material chemistry, Brno university of technology, Purkynova 118, 612 00, Brno;

email: [email protected]

Keywords: ethyl lactate, lactic acid, transesterification

Ethyl lactate is a promising bio-solvent that can be prepared from renewable raw materials. Its properties such as low volatility, high dissolution strength, miscibility with water and organic phase and environmental and health harmlessness make it a unique among solvents prepared from non-fossil raw materials. Wider use complicates difficult synthesis by direct esterification of the lactic acid with ethanol, which is complicated by the auto-condensation of lactic acid and ethyl lactate to non-volatile oligomers and the inappropriate boiling points sequence of the components in the esterification mixture.

Ethyl lactate forms azeotropic mixture with water1, which

is natural by-product of esterification. Current progressive but still young technologies for ethyl lactate synthesis are based on a reactive distillation

3 or

pervaporation separation2 of water from the mixture. To

overcome difficulties of synthesis using just conventional unit operations a new two-step process for synthesis anhydrous ester based on the transesterification of oligomeric lactic acid with ethanol has been proposed.

In the first step of synthesis, crude lactic acid in the form of an aqueous solution is auto-catalytically condensed to an oligomer having 5 to 20 lactate units. During the condensation phase, virtually all water from the reaction medium is removed. In the second step, is oligomer transesterified with anhydrous ethanol in equimolar ratio with respect to lactate units. Ethanol and the lactic acid oligomer together with the catalyst form homogeneous solution that allows rapid reaction. The proposed semi-continuous technology allows complete recycling of the oligomeric ester distillation residuum and homogeneous catalyst. Ferric chloride was used as an efficient and ecological catalyst for transesterification.

Removal of the water prior to ester synthesis has a positive effect on the equilibrium composition–yield of the ester. Use of an excess of ethanol in the esterification mixture to shift the equilibrium is eliminated.

Figure 3: Schematic of two-step process for ethyl lactate synthesis

To describe reaction equilibrium with the equimolar ratio of reactants a kinetic model was derived to determine the basic parameters of the transesterification process. The model allows determination of speed and equilibrium constants and the equilibrium composition of the mixture with respect to ethanol. Together with the obtained dependence of these parameters on temperature it is possible to predict the course and result of transesterification. Results of the study were used to obtain basic energy, time and material balance. The basic concept of new process was created.

Reference [1] T. Dung, C. T. Lira, N. S. Asthana. J. Chem. Eng. Data, 51 (4), 1220–1225, 2006 [2] T. Sanz, S. Beltran, Chemical Engineering Journal, 693-700, 2010 [3] B.H. Lunelli, D.I.P. Atala, N. Oliveira, Journal of Biotechnology, 150, 569-569,2010

35

Development of New Voltammetric Approach for Determination of

Plant Hormones Employing Boron-Doped Diamond Electrode as a

Sensor

Jaromíra Chýlková1, Lenka Janíková1, Miloš Sedlák2, Jiří Váňa2, Renáta Šelešovská1

1 University of Pardubice, Faculty of Chemical Technology, Institute of Environmental and Chemical

Engineering, Studentská 573, 532 10 Pardubice, Czech Republic

E-mail: [email protected] 2 University of Pardubice, Faculty of Chemical Technology, Institute of Organic Chemistry and

Technology, Studentská 573, 532 10 Pardubice, Czech Republic

Keywords: phytohormone, indole-3-acetic acid, indole-3-butyric acid, 1-naphtylacetic acid,

voltammetry, boron-doped diamond electrode

Plant hormones, a diverse group of signaling compounds, which could be found in minor amounts in plant cells, play crucial role in the plant regulation of growth and development [1,2]. Many of them are used as synthetically prepared growth stimulators. Considering their biological activity and application as synthetic stimulators, various analytical tools, including electrochemistry, have been introduced for their monitoring, e.g. [3,4].

Three representatives of auxin phytohormone group, namely indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), and 1-naphtylacetic acid (NAA), were chosen for purposes of our work. The structures of the analyzed auxins are depicted in Figure 1. A boron-doped diamond electrode (BDDE) was employed as a working electrode in the study due to its unique electrochemical properties, e.g. [5,6].

Figure 1: Chemical structures of the analyzed compounds

The first aim of our work was to examine voltammetric behavior of IBA and NAA due to the lack of

information in the literature. It was found, that both substances easily undergo electrochemical oxidation. In slight acidic medium, which were found as optimal for further analytical studies, IBA and NAA as well provided one signal corresponding to oxidation recorded on BDDE. Parameters of differential pulse voltammetry (DPV), a sensitive voltammetric technique, were optimized and it was reached low limit of detection (LODIBA = 0.16 µg/mL; LODNAA = 0.35 µg/mL) and quantification (LODIBA = 0.52 µg/mL; LODNAA = 1.18 µg/mL) as well.

The second goal of our research was to develope simple, sensitive, and precise voltammetric method for simultaneous determination of IBA and NAA, respectively, in presence of IAA. IAA provided two oxidation peaks at about similar potentials as IBA (the first peak of IAA) and NAA (the second peak of IAA), respectively. In case of IBA, the derivative step of the particular part of the curve was sufficient for the proper evaluation. On the other hand, more acid supporting electrolyte (0.6 M H2SO4 at least) was suitable for correct determination of NAA in presence of IAA. NAA provided two signals in this medium and the positively situated one was not influenced by presence of IAA and could be used for the determination. The applicability of the designed method was verified by analysis of the commercially available growth stimulator formulas with excellent results.

References [1] T. Gaspar, C. Kevers, O. Faivre-Rampant, M. Crevecoeur, C. Penel, H. Greppin, J. Dommes, In Vitro Cell. Dev. Biol.-Plant 39 (2003) 85. [2] S.H. Wani, V. Kumar, V. Shriram, S.K.Sah, The Crop Journal 4 (2016) 162. [3] Y. Bai, F. Du, Y. Bai, H. Liu, Anal. Method. 2 (2010) 1867. [4] F. JiHong, S. XiaoHong, W. JiDe, C. JinFang, Y. CunYu, Plant Physiol. 56 (2011) 355. [5] G.M. Swain, R. Ramesham, Anal. Chem.. 65 (1993) 345. [6] A. Kraft, Int. J. Electrochem. Sci. 2 (2007) 355.

Acknowledgement This work was supported by the grant project of The Czech Science Foundation (project No. 17-03868S) and by The

University of Pardubice (SD373001/82/30350(2016)).

36

Distinguishing the PET quality for its recycling

Lucie Kabelíková1, Jiří Kučerík1

1 Brno University of Technology, Faculty of Chemistry, Institute of Chemistry and Technology

of Environmental Protection, Purkyňova 118, Královo Pole, 61200, Brno, Czech Republic,

[email protected]

Keywords: PET, recycling, degradation, stability

Due to the huge amount of produced polymer materials, it is necessary to offer a wide range of satisfactory options for further processing. Different types of chemical and mechanical recycling are currently being applied. As an ideal solution with low environmental burden appears the mechanical recycling, it has still, however, several limitations.

The main problem is that the collection system for recycling produces a mixture consisting of a wide range of plastic materials. The modern sorting machines enable the separation of PET from other plastics, but it does not allow sorting of different types of PET according to their quality. This may lead to other problems. For example, food grade recycled material should not contain more than 5% of PET originating from the packaging of household chemicals. Therefore, there is a need for a technology that helps to separate PET according to its “quality”. In addition, PET flakes originating from the multiple recycled PET are known for "graying" caused by admixtures of other plastics, which causes other problems. On the contrary, some studies have reported that low quality (degraded) PET can be used for some applications, due to easier PET crystallization and processing. [1–3]

The problems with PET quality can partially be solved by high-temperature re-granulation, when physical and chemical changes occur in the polymer and volatile substances are removed. This increases the PET purity (up to food grade), but also considerably increases the price of the products.

However, the study of degradation of re-granulates gives only partial information about PET's behavior during the recycling cycled. Therefore, the aim of this work is to analyze different types of PET materials of different origin and recycling degree. 14 different samples of PET were studied including direct products of virgin materials and products that underwent multiple physical recycling. For comparison also analyzed regranulates, for food and non-food purposes. As a control sample, virgin PET is considered here.

Thermal properties of PET were analyzed using differential scanning calorimetry device TA Instrument DSC 2500 with a repeating thermal heating and cooling cycles of 5°C/min to 320°C. Both the first heating, with emphasis on PET thermal history, and the second heating, used for determination of all phase transformations, were investigated. Based on these data is searched a correlation between parameters, such as the glass transition and melting temperature and enthalpy.

The thermo-oxidative stability of these PETs samples were investigated by means of thermogravimetric analysis by using TA Instrument TGA 550. To stability was determined by determination of the degradation onset at different heating rates.

The data were also used to identify different types of PET and determine at what stage of the recycling cycle is the investigated, as suggested by some studies. This should lead to determine the best method for further treatment of the unknown sample in PET recycling.[4]

References [1] J. D. Badía, F. Vilaplana, S. Karlsson, and A. Ribes-Greus, “Thermal analysis as a quality tool for assessing the

influence of thermo-mechanical degradation on recycled poly(ethylene terephthalate),” Polym. Test., vol. 28, no. 2, pp. 169–175, 2009.

[2] L. K. Nait-Ali, X. Colin, and A. Bergeret, “Kinetic analysis and modelling of PET macromolecular changes during its mechanical recycling by extrusion,” Polym. Degrad. Stab., vol. 96, no. 2, pp. 236–246, 2011.

[3] R. Assadi, X. Colin, and J. Verdu, “Irreversible structural changes during PET recycling by extrusion,” Polymer (Guildf)., vol. 45, no. 13, pp. 4403–4412, 2004.

[4] D. H. Kang, R. Auras, K. Vorst, and J. Singh, “An exploratory model for predicting post-consumer recycled PET content in PET sheets,” Polym. Test., vol. 30, no. 1, pp. 60–68, 2011.

Acknowledgement This work was financially supported by project FCH-S-18-5331 of the Ministry of Education, Youth and Sports of the Czech Republic.

37

Removing CO2 from Air Masses by a Pilot-Plant Scubber Equipped

With a Spiral Nozzle

Josef Kalivoda1, Tomáš Svěrák2, Ondřej Krištof1, Kateřina Mayerová1

1 Brno University of Technology, Faculty of Mechanical Engineering, Heat transfer and Fluid Flow

Laboratory, Technická 2896/2, 616 69, Brno, Czech Republic, [email protected] 2 Brno University of Technology, Faculty of Chemistry, Institute of Materials Chemistry

Keywords: gas absorption, absorption with chemical reaction, liquid scrubber, gas treating

The experimental work was completed on the pilot plant scrubber equipped with spiral PTFE nozzle. The pilot plant scrubber was developed in cooperation with process engineering company (MVB Opava s. r. o.) from Czech Republic. The scrubber is special type of the mass transfer device which offers lesser pressure drop, better cost effectiveness and simpler maintenance in compare with other gas-liquid contact devices. Design of the liquid scrubber allows work under steady, or unsteady conditions.

The experimental work was focused on removing of 0.2, 0.5 and 0.8 %vol. of CO2 in air masses by 1 %mass NaOH under different hydraulic conditions. Pressure drops, liquid holdup, gas/liquid contact time, capture efficiency was calculated for the different conditions. The experiments were measured under pseudo-steady state conditions due to the circulated sodium hydroxide solution in the system.

Figure 1: CO2 capture efficiency

The efficiency of the carbon dioxide capture shows fig. 1. As it can be seen the efficiency is increasing with the pressure of the liquid in the spiral nozzle. The increasing pressure leads to the more efficient atomization of the liquid thus the interfacial area is rapidly increased. On the other hand, the best obtained efficiency is about 69 percent. It is far away from the expected values. Possible explanation can be that the inner volume of the sparkling head is not effectively covered with liquid drops spray and thus the contact between liquid and gas is insufficient. This can be improved with installation two or more nozzles in to the sparkling head. Two or more nozzles should help with better coverage of inner volume by liquid drops and improve the contact between gas and liquid to the more efficient values.

Acknowledgement This work was supported by the Technology Agency of the Czech Republic as a project TH01030820.

50

55

60

65

70

0.0 0.5 1.0 1.5 2.0 2.5

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%)

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0.2 %vol. CO2

–0.20 mbar –0,80 mbar –1,40 mbar

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–0.20 mbar –0.80 mbar –1.40 mbar

38

Platinum nanoparticles in the environment and their impact on soil

Renata Komendová1, Michal Berka1, Jiří Kučerík1

1 Brno University of Technology, Faculty of Chemistry, Institute of Chemistry and Technology of

Environmental Protection, Purkyňova 464/118, 61200 Brno, Czech Republic,

[email protected]

Keywords: platinum, nanoparticles, environment, soil, autocatalyst

The nanomaterial can be defined as a chemical or material composed of particles whose size is at least in one direction from 1 to 100 nanometers. In many cases, nanomaterials have different properties than the same material at the macro level. For example, platinum is considered a biocompatible material and is therefore used to make endoprostheses and pacemakers. On the other hand, platinum nanoparticles are very dangerous due to their catalytic capabilities. They pass easily through the cell membrane, and as a result of inhalation, inflammation of the lung occurs very often. In nature, however, rapid clumping occurs in larger particles [1], which have a positive effect on the reduction of their toxicity.

The problem of nanoparticles of platinum metals has not been given much attention yet. There is a risk of environmental contamination by these nanoparticles. The reason is the massive use of cars with the mandatory equipment of the automotive catalyser. Platinum metals

(platinum, palladium and rhodium) form an active layer of these catalysts, which are used to reduce emissions of carbon monoxide, hydrocarbons and nitrogen oxides [2].

During these catalytic reactions, platinum and other platinum metal particles escape into the surrounding atmosphere. Consequently, all the components of the environment are contaminated and variety of natural processes can be affected [3]. Platinum can be released in the elementary state, in the oxidized particles, bound to other emitting substances or in the form of nanoparticles.

In this work, a model soil was spiked by 3 nm-sized Pt nanoparticles to observe their influence on the strength of water binding, stability of the water molecule bridges (WaMB) and the water retention in the soil. A wide range of concentrations was analyzed to find the threshold at which the nanoparticles influence significantly the investigated parameters.

References

[1] B. Roldan Cuenya, M. Alcántara Ortigoza, L. K. Ono, F. Behafarid, S. Mostafa, J. R. Croy, K. Paredis, G. Shafai, T. S.

Rahman, L. Li, Z. Zhang, and J. C. Yang, Phys. Rev. B 84, (2011) 245438.

[2] Y. Wang, X. Li, Procedia Engineering 45 (2012) 1004. [3] J. Pawlak, E. Łodyga-Chruścińska, J. Chrustowicz, Journal of Trace Elements in Medicine and Biology 28 (2014) 247.

Acknowledgement This work was supported by the institution research plan No. FCH-S-18-5331 from the Ministry of Education, Youth and Sports of the Czech Republic.

https://www.sciencedirect.com/science/journal/0946672X

39

Possibilities of water and energy storage in the environment of fast-

growing trees

Kotlík, J., Půčková, H., Levek, P., Mikšík, F.,

1 Brno University of Technology, Faculty of Chemistry, Purkyňova 464/118, 61200 Brno, Czech

Republic, [email protected]

Cultural plantations of hybrids of short-rotation hybrids (SRC) are attractive to some farmers or landowners due to the potential for energy production. The introduction of plantations and the use of wood energy from SRC plantations could be ecologically effective even for capturing water in the landscape. On

the territory of Slovakia and the Czech Republic are monitored some Italian and Japanese poplar clones with a wide ecological amplitude. The influence of fast growing trees on the environment is not entirely positive, as is commonly known in the literature.

40

Linking soil microbial quality indicators and thermo-oxidative

stability

Jiří Kučerík1, Karel Svatoň1, Stanislav Malý2, Martin Brtnický3, Christian Siewert4


Environmental Protection, Purkyňova 118, 62100 Brno, Czech Republic, [email protected] 2 Central Institute for Supervising and Testing in Agriculture, Hroznová 2, 656 06 Brno, Czech Republic

3 Mendel University, Faculty of Forestry, Institute of Geology and Pedology, Zemědělská 3, 61300 Brno, Czech

Republic. 4 Technical University Berlin, Institute of Ecology, Chair of Soil Conservation, Ernst-Reuter Platz 1, 10587

Berlin, Germany

Keywords: soil quality indicators, thermogravimetry, soil organic matter, degradation

Soil is a complex system consisting of organic and mineral compartments, biota, water and air that are interrelated via biogeochemical cycles. Although soil organic matter (SOM) and soil microbial biomass represent usually only a small part of this system, especially in minerals soils, they assure a large number of functions and play a dominant role in soil properties. For a long time, soil and its “quality” have been recognized as a key factor in survival and development of human civilizations. However, there is still not a consensus how to define soil quality, which leads to the use of a multitude of different approaches. The reason are factors such as large number of soil types, complexity of soil composition and poor understanding the soil forming processes [1]. For this reason, instead of applying a universally applicable soil quality standard, only soil quality indicators (SQI) are used.

Three groups of soil properties considered as SQI are recognized: chemical, physical and biological. The chemical indicators include pH, total organic C, nutrient level, electrical conductivity; among physical indicators belong soil texture, rooting depth, infiltration rate, bulk density, water retention capacity and biological SQI are represented by C and N microbial biomass, potentially mineralizable N, soil respiration and others.

The SQI have different sensitivity towards shifts in soil processes and composition. The physical SQI response mainly to drastic soil changes, whereas the biological and biochemical SQI are sensitive even to very slight soil modifications, e.g. to a low concentration of degrading agent. Hence, the SQI should always include biological, biochemical and chemical parameters, which are sensitive and response fast.

The determination of a number of individual indicators using standard procedures is usually laborious and/or time consuming. It is, therefore, of a great interest to develop faster and less laborious approaches enabling fast and reliable assessment of shifts in SQI. This problem can be solved by the replacement of the common procedures using a validated analytical technique, which enables a routine analysis of a large number of samples followed by an automatized data evaluation.

TG is based on monitoring of mass change of a sample as a function of programmed temperature regime (usually linear heating). TG provides both quantitative (mass loss signal) and qualitative (temperature signal) information. The thermal mass losses obtained by thermogravimetry closely correlate with soil organic carbon, total nitrogen and clay contents [2]. These correlations are very important for fast analysis of soil properties, but to reflect the complexity of soil processes, it is necessary to define also other connections, primarily those reflected by microbiological SQI. In addition, the correlation requires the pre-conditioning of soils prior to analysis at 76% relative humidity, which may be problematic for routine laboratory applications. We address these issues and present new correlations and equations connecting thermal mass losses and some microbiological SQI including the biomass C and N, basal and substrate induced respiration, specific growing velocity of microorganisms, anaerobic ammonification and activity of urease. Importantly, these connections were obtained at 43% relative humidity, which is closer to common laboratory conditions.

References [1] Minasny, B., A.B. McBratney, and S. Salvador-Blanes, Quantitative models for pedogenesis - A review. Geoderma,

144 (2008) 140 [2] Siewert, C., Rapid screening of soil properties using thermogravimetry. Soil Science Society of America Journal, 68

(2004) 1656

Acknowledgement This work was financially supported by project FCH-S-18-5331 of the Ministry of Education, Youth and Sports of the Czech Republic.

41

System of efficient use of heat, water and electricity in family

houses

Petr Levek, Milada Vávrová, Josef Kotlík, Helena Půčková, František Mikšík, Silvie Kotlíková

Ústav chemie a technologie životního prostředí Fakulty chemické, VUT Brno, Purkyňova 118, 612 00

Brno, [email protected]

Keywords: renewable sources of energy, water, rainwater, regulation, photovoltaic panels, energy

self-sufficiency

The first known systems for the use of renewable resources have been known for many years when hydroelectric power stations have helped us with the production of energy. New trends from the last century have also brought about the expansion from other directions, such as photovoltaics, since the first installation of photovoltaic panels in the Czech Republic has passed for more than 15 years. During that time many things have changed, but the photovoltaic panels are still on our market and in greater numbers, not only because of state subsidies to various renewable sources.

It is becoming increasingly possible to see photovoltaic panels or rainwater collectors in a small number on family houses, where a private user is trying to get at least some of the renewable resources for his benefit or to stick to financial support for the subsequently sold electricity.

Not only because the focus is on systems for small users, such as family homes and small businesses with ordinary consumption up to 10kWh, which solves the issue of economic indicators of such systems or usability of water saving solutions. Solution ecology is not available and in most cases is a secondary objective. The main goal for these smaller users thus remains a quick return and subsequent gain in terms of maximum possible energy self-sufficiency. In this respect, the

saving of water seems very interesting, as the customer can save many thousands of Czech crowns a year despite the lower cost of entry and at the same time contribute to better water management and therefore ecology.

To achieve optimum results in addition to the implementation of appropriate elements, reduction of consumption, use of modern energy-saving appliances and saving aids, efficient use of energy, the possibility of regulation, thanks to the data and predictions. The best optimal wiring for houses at acceptable cost with a return in about 12 to 15 years, and the use of photovoltaic panels, battery storages and, heat pumps; today reached during the lifetime value of more than 70% self-sufficiency. For larger investments, according to the results we can achieve complete energy independence much earlier, but economic indicators are for ordinary users, in most cases, unacceptable. Our goal is for all implementations with the use of our control and with the help of the company Ekoenergie. Achieving levels of about 80% energy self-sufficiency, has been since the first day of commissioning of the system. These complete systems for regular users and owners of family homes would estimate a planned reduction cost, with the total overall value return in the time-frame of 8 years maximum.


42

Preliminary Investigation into the Stimulation of Plant Growth

Promoting Bacteria (Pgpb) by Soil Amendment With a Commercial

Humic Acid

Karen Little1, Han Ming Gan2, Michael Rose3, William Roy Jackson1, Timothy Cavagnaro4 and Antonio

Patti1.

1 Monash University, School of Chemistry, Clayton, Victoria, Australia. [email protected] 2 Deakin University, School of Life and Environmental Sciences, Geelong, Victoria, Australia. 3 NSW Department of Primary Industries, Wollongbar, New South Wales, Australia. 4 University of Adelaide, School of Agriculture, Food and Wine, Glen Osmond, South Australia.

Keywords: humic, next generation sequencing, plant growth promoting bacteria, rhizobium

The stimulation of, or soil inoculation with plant growth promoting bacteria (PGPB) is recognized as a potential means of decreasing fertilizer inputs, the benefits of which are to decrease greenhouse gas emissions, nitrate run off and soil acidification. Rhizobium form symbiotic relationships with leguminous plants and supply nitrogenous compounds by fixing atmospheric nitrogen. Advances in high-throughput 16S rDNA amplicon sequencing technologies provide a considerable amount of taxonomic information and have changed our understanding of microbial diversity in the environment. In an incubation study, application of a commercial humic acid product was shown to increase the abundance of bacteria of the Proteobacteria phylum, specifically the Rhizobiales order and therein the Beijerinckiaceae, Bradyrhizobiaceae, Hyphomicrobium and Rhizobiaceae families.

The lignite-derived amendment used for this study was a commercially available, soluble, potassium humate in granular form (SHG) and was applied to a sandy soil, low in organic matter and nutrients, at rates

of 0, 20 and 300 kg/ha. The addition of SHG increased

soil CO2 emissions, indicating stimulation of the soil microbial community. Sequences belonging to 25 bacterial phyla were identified. The dominant phyla were Actinobacteria (28–35%), Proteobacteria (21-31%), Chloroflexi (6-11%), Planctomycetes (6-8%) and Acidobacteria (8-10%), phyla that are commonly dominant in soil (Fig. 1). Of particular interest was a significant increase in the abundance of Proteobacteria (p=0.02) between the unamended soil and the 300 kg/ha application rate. Within the Proteobacteria phylum, there was a significant increase in the Rhizobiales order and therein the Bradyrhizobiaceae, Beijerinckiaceae Hyphomicrobium and Rhizobiaceae families, with increasing SHG application. The shift in microbial community composition with SHG amendment was further demonstrated by abundance data clustering according to application rate (Fig. 2). The results of this preliminary study gives some insight into the growth promoting effects of commercial humic acids. Further investigation is required using a range of humic products, in a broader range of soil types and in the presence of

plants. Further identification of the bacteria to the operational taxonomic unit level (OTU) and microbial functional assays would be required to extend on the knowledge gained here.

Fig. 1: The percentage abundance of bacterial phyla with application of SHG.

Fig. 2 Non-metric multidimensional scale analysis of the abundance of the Bradyrhizobiaceae, Beijerinckiaceae Hyphomicrobium and Rhizobiaceae families using Bray

Curtis similarity index. The numbers within each cluster

represent the application rate of SHG.

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43

Assessment Adsorption behavior of K-Humat (Tki- Hümas) on

carbon nanotubes from soil by provided E4/E6 ratios in different

incubation times

Abdelbagi Mohamedelnour1, Muhittin Onur Akça1, Sonay Sözüdoğru Ok1

1 Department of Soil Science and Plant Nutrition, Faculty of Agriculture, Ankara University,

[email protected] / [email protected]

Keywords: functionalized carbon nanotubes, K-Humat, Adsorption, (E4/E6) ratios,

spectrophotometer

The behavior of humic acid (HA) and carbon nanotubes (CNTs) in the environment is a prominent concern, but the suspending mechanism of functionalities on their sorption is still unclear.

In the presented study, functionalized multi-walled

carbon nanotubes (fMWCNTs) and K-Humat (Tki- Hümas) were used to study their sorption behavior on the soil, by providing 465 and 665 nm (E4/E6) ratios of adsorbances of humic and fulvic acid (K-Humat) extracted from clay soil.

E4/E6 ratios it has been suggested by soil scientists is

related to the degree of condensation of the aromatic carbon network, carbon content, and molecular weight of humic substances, little rigorous experimental evidence is available in the literature to confirm these hypotheses.

Generally, the results showed that the functionalized

multi-walled carbon nanotubes have a significant effect on K-Humat adsorption at different incubation time. This study demonstrated the feasibility importance of functionalized multi-walled carbon nanotubes as an adsorbent in removing organic pollutants from soil.

Table (1): humat from TKI content

Humat content % (W/W)

Total organic matter 5.0

Total (Humic + Fulvic acid) 12.0

water-soluble potassium oxide 2.0

pH 11-13

Table (2): Technical Properties of fMWCNTs

Purity > 96 wt %

Content of (COOH) 2.2 wt %

Color black

Outside Diameter 8-18 nm

Inside Diameter 5-10 nm

Length 0.5-2 um

SSA 210 m2/g

figure (1): TKI-humat



44

Analysis of organic compounds in biochar produced by pyrolysis of

sludge

Ludmila Mravcová1, Flávia Bittencourt Moré2, Jakub Raček3, Jan Ševčík3, Josef Čáslavský1, Milada

Vávrová1

1 Brno University of Technology, Faculty of Chemistry, Purkynova 118, Brno 61200, Czech Republic 2 The Universidade Federal de Santa Catarina, Department of Sanitary and Environmental

Engineering, Florianopolis, Brazil 3 Brno University of Technology, AdMaS Centre, Faculty of Civil Engineering, Purkynova 139, Brno

61200, Czech Republic

The largest part of energy production is realized by the burning of fossil fuels, the resources are depletable and their using causes the environmental pollution. Because of this, renewable sources of energy are constantly being sought, for example generation of gas from biomas and waste product (eg. sludge from sewage treatment plants) by pyrolysis and combustion processes.

Pyrolysis is a thermochemical process (decomposition) without the presence of oxygen. The products can be divided into gas, liquid (pyrolysis oil) and solid residue (biochar). The gas mainly contains CO, H2, CO2, nitrogen oxides, CH4 and other low molecular weight hydrocarbons. The oil is composed from hydrocarbons with a high number of carbon and other organic compounds. The carbonaceous residue is composed from unreacted particles of decomposed material, mainly charred matter and ash. Biochar could be applied to soil for the carbon enrichment and better physical qualities. Pyrolysis of organic material is known

to produce a wide variety of low and high molecular weight aromatic coumpounds (PAHs) and their derivatives depending on the biomass type, pyrolysis conditions and kinetic factors.

In this work, the microwave pyrolysis under low temperature conditions was used for the processing of sludge from the waste water treatment plant. Especially, we analysed the biochar, as one pyrolysis product, for PAHs content. The pressurized solvent extraction (PSE) was used for extraction of PAHs into dichlormethane. The extract was cleaned by silicagel column and the fraction contain PAHs was analyzed using gas chromatography with time of flight mass spectrometry detection (GC-TOF MS).

This work was supported by Ministry of Education, Youth and Sports of Czech Republic, grant No. FCH-S-18-5331 and under the project No. LO1408 „AdMaS UP-Advanced Materials, Structures and Technologies“, supported by Ministry of Education, Youth and Sports under the „National Sustainability Programme I“.

45

Possible solutions for process monitoring on the wastewater

treatment plants

Michal Petruľák1, Josef Čáslavský1


Environmental Protection, Purkyňova 464/118, 612 00 Brno, Czech Republic,

[email protected]

Keywords: wastewater, treatment, process monitoring, on-line sensor

A clean environment is the basis for a healthy life. Keeping the environment clean for the protection of all creatures should be the primary responsibility of any society. In Europe alone, there are numerous laws, ordinances and administrative regulations describing the environmental conditions needed to ensure a certain environmental standard. Instrumental analysis is a useful tool to measure the status of environmental conditions, but also to monitor and optimize the technological processes. Instrumentation for the process control and process monitoring is a hidden, but important technology. Various sensors which are being developed for the more precise and efficient wastewater treatment process control and monitoring are nowadays available on the market [1]. Different principles of measurement are applied. One of the most widespread are the

photometric or other optical methods and the potentiometric methods. In order to achieve best possible wastewater treatment plant operation efficiency as well as nutrient removal efficiency, the data are the lifeblood in any automated system. They form the basis for the entire logging, analysis and any proof of quality. These data are the key for the optimization of operational processes and for the increase of productivity, quality, safety and profitability of investments [2].

This contribution will provide an overview of various available sensors types and their field of applications for the monitoring of wastewater treatment process. Furthermore, the principles of their operation will be described and discussed.

References [1] http://www.wtwcz.com/system-iq-282-284-169/. Downloaded on May 15, 2018. [2] S. Isaacs, H. Temmink, Water Science and Technology 33 (1996) 165.

Acknowledgement This work was supported by the specific research project FCH-S-18-5331 “Pollution of the environment and possibilities

of elimination of contaminants” from the Ministry of Education, Youth and Sports of the Czech Republic.

http://www.wtwcz.com/system-iq-282-284-169/

46

The Role of Alkalis In Hydraulic Mixtures

Prochazka, L.

Brno University of Technology, Faculty of Chemistry, Purkyňova 464/118, 612 00 Brno, Czech


Alkali substances are present in cements used as a binder in concrete only in a minimum content. The most known process that alkali causes is the alkali-silica reaction. In this reaction, the alkali contained in the cement or supplied from the outside with an inappropriately selected aggregate containing amorphous SiO2. This reaction results in the development of hydration products, resulting in an increase in the volume of the original components, which can cause a breakage of the concrete structure and subsequent disintegration. The range of alkali-silica reaction can be reduced by the use of a suitable

aggregate or the use of Type II admixtures which are characterized by pozzolanic or latently hydraulic activity. These admixtures react with alkali and then no longer react with the amorphous SiO2 contained in the aggregate. Alkals also affect other properties of concrete such as basic physical-mechanical properties, frost resistance and pH.

In the experimental part the pH values were compared between mixtures of Portland cement and alkaline activated blast furnace slag using slag aggregate from the heap Koněv.

47

Environmental aspects of fast growing trees

Puckova, H., Kotlik, J., Levek, P., Miksik, F., Kotlikova, S., Caslavsky, J.

Brno University of Technology, Faculty of Chemistry, Purkyňova 464/118, 612 00 Brno, Czech

Republic

Keywords: Fast growing trees, SRC, RES, Populus, Environment, Landscape

Short rotation coppice (SRC) of fast growing trees are

plantations of tree species, such as in Europe poplar (Populus spp.) and willow (Salix spp.), which, due to rapid increases in wood are established on agricultural land and harvested in rotations of 3 – 10 years, depending on tree species, environment and management conditions and grown to coppice system. Coppicing involves cutting the tree back down to near ground level.

The wood, which is harvested, can then be used as a fuel and the tree grows back until it is ready for harvesting again. Traditionally, hazel and chestnut trees have been grown on this system. Major advantage is that production technology is known since long and the energy may be stored a long time after harvesting. Wood chips from SRC have better fuel properties than other renewable raw materials such as miscanthus or straw. When used for electricity generation wood chips from SRC create lower CO2 emissions than straw but slightly higher CO2 emissions than forest residues. Furthermore, SRC is more productive per area unit than natural forest in Europe and is also ecologically advantageous in comparison to more input-intensive

agricultural energy crops such as corn and rape. In the home wood can be burned to provide both space and water heating. It can also be used to provide the hot water and space heating needs of larger buildings.

In contrast to other renewable energy sources (RES), socio-economic and policy aspects rather than technological aspects are fundamental to increasing the supply of energy from biomass. An important aspect may be water retention in the landscape. The few technological aspects which need to be improved with regard to SRC cultivation are harvesting techniques and optimization of use-specific logistic chains. SRC plantations of hybrid poplars are attractive for some farmers or owners of agricultural land due to the potential for energy production. Introducing plantations and using wood energy from SRCs can have a negative impact on the environment. On the territory of the Slovakia are monitored by some Italian poplar clones with broad ecological amplitude. The results of observations lead to the conclusion not too encouraging for some growers of fast growing trees. The influence of SRC on the environment is not entirely positive, as is commonly known in the literature.

Acknowledgements This work was supported by Ministry of Education, Youth and Sports of the Czech Republic (FCH-S-16-3364).

48

Artificial sweeteners in water

Martina Repková1, Nikola Dalajková2, Libuše Vítková3

1 BUT Faculty of Chemistry, Czech Republic, Institute of Environmental Chemistry,

Purkyňova 464/118, 612 00 Brno, [email protected] 2 BUT Faculty of Chemistry, Czech Republic, Institute of Environmental Chemistry 3 BUT Faculty of Chemistry, Czech Republic, Institute of Environmental Chemistry

Keywords: artificial sweeteners, sucralose, saccharin, AOP processes, waste water, WWTP

Artificial sweeteners, the ingredients of dietary products,

are consumed considerably in food, beverages, drugs

and sanitary products. Replacement sweeteners,

together with other substances, are recognized as a new

class of water contaminants. This was mainly due to the

proven or potentially adverse effects on human health

and aquatic ecosystems. Some of the artificial

sweeteners are difficult to degrade by conventional

wastewater treatment processes. Consequently,

advanced oxidation processes (AOPs) have been

proposed as an alternative method to degrade artificial

sweeteners effectively [1-3].

The aim of this work is the determination of artificial

sweeteners in waste water from wastewater treatment

plant (WWTP) Modřice and the subsequent degradation

of the thus obtained concentrations in model water

using advanced oxidation processes. Two sweeteners

were determined, namely sucralose and saccharin found

in waste water. Synthetic sweeteners are not sufficiently

cleaned in the WWTP and penetrate the environment.

Effective processes for removing organic substances,

including alternative sweeteners, are AOP processes.

These processes are based on reactions of highly

reactive hydroxyl radical (OH·), which is produced by

many chemical reactions. Generally, they use ozone (O3)

and hydrogen peroxide (H2O2). On sampling, wastewater

samples were treated with Solid Phase Extraction (SPE)

and then evaluated by HPLC/MS (High Performance

Liquid Chromatography). The concentrations of

sweeteners found in samples from Modřice WWTP were

subjected to three AOP methods: O3/UV, H2O2/UV and

O3/H2O2. For each of these methods, the efficiency of

degradation of sucralose and saccharin was investigated.

From the evaluated data it was found that the most

efficient AOP process for removing artificial sweeteners

from water is the O3/H2O2 method [4].

References

[1] TRAN, Ngoc, Martin REINHARD a Karina GIN. Occurrence and fate of emerging contaminants in municipal wastewater treatment plants from different geographical regions-a review. Water Research 133 (2018)

[2] HENG, Lin, Oturan NIHAL, Jie WU, Virender K. SHARMA, Hui ZHANG a Mehmet A. Oturan. Removal of artificial sweetener aspartame from aqueous media by electrochemical advanced oxidation processes. Chemosphere 167 (2017)

[3] KOKOTOU, Maroula, Alexandros ASIMAKOPOULOS a Nikolaos THOMAIDIS. Artificial sweeteners as emerging pollutants

in the environment: analytical methodologies and environmental impact. Analytical Methods 4 (2012)

[4] DALAJKOVA, Nikola. Odstranění vybraných organických polutantů z vody s využitím pokročilých oxidačních procesů. Brno, 2018. Diplomová práce. VUT Brno.

Acknowledgement This work was supported by the specific research project No. FCH-S-18-5331 from the Ministry of Education, Youth and

Sports of the Czech Republic.

49

Spectrophotometric determination of chlorophyll in tests of

phytotoxicity

Veronika Řezáčová, Petra Rábová, Helena Zlámalová Gargošová

BUT Faculty of Chemistry, Institute of Chemistry and Technology of Environmental Protection,

Purkyňova 118, 612 00 Brno, Czech Republic; [email protected]

Keywords: spectrophotometry, chlorophyll, phytotoxicity

Photosynthesis is a basic yet complex process sustaining the life of all plants. It is a complex process in which the energy captured from the light powers cascade of chemical reaction resulting in synthesis of organic matter and oxygen from inorganic substances. A green pigment found in cyanobacteria and chloroplasts of algae and plants called chlorophyll is the key molecule for the process.

Natural process in plants may be affected by a wide diversity of external factors, such as temperature and water stress, atmospheric pollution, light conditions, unfavorable soil, biotic factors or toxic effects. In order to evaluate the impact of some of the stress factors, the phytotoxicity tests are used. Those include evaluation of important ecotoxicological indicators where endpoints such as seed germination, root elongation or biomass production.

Negative factors have a harmful effect on the growth of the plant and also on the concentration of chlorophyll contained in it. The properties of chlorophyll and its good solubility in organic solvents enable to perform the extraction-spectrophotometric method.

One of the standard phytotoxicity test is the ISO 20079:2005 test, which specifies the method for determining the growth-inhibiting response of duckweed (Lemma minor) to municipal wastewater and industrial effluents. The result is value of IC50 (the concentration of the toxicant that causes 50% inhibition of growth).

The contribution presents the results of the determination of the effect of the control substances (potassium dichromate) on the aquatic plant duckweed (Lemna minor). The exposure time was 168 hours and the concentrations of dichromate were 0, 10, 20, 40, 80 and 160 mg.dm

-3.

The effect of this substances was evaluated via two independent endpoints, namely by biomass and by spectrophotometric determination of chlorophyll, newly used in our labs.

The leaves from each tested concentration were ground up with magnesium carbonate after the exposure time for spectrophotometric determination. Acetone 80%

was used to extract the chlorophyll. This solvent was chosen because of the good extraction efficiency and the numerous applications.

The results of the spectrophotometric determination which document decreasing concentration of chlorophyll in respect to increasing concentration of toxicant are shown in Fig. 1.

Figure 1: Absorption spectra of extracted chlorophyll solutions

Both methods of evaluation, i.e. using quantity of biomass or chlorophyll as endpoints, reflect the xenobiotic effects. The results correlate with each other. Spectrophotometric determination of chlorophyll amount as was confirmed by our results, appears as a suitable extension of the usual evaluation methods in phytotoxicity tests.

Acknowledgement This work was supported by Project No. FCH-S-18-

5331.

50

From Chemistry to Technology - Biomass Gasification Product Gas

Cleaning and Utilization

Petr Seghman1, Tomáš Jirout1, Lukáš Krátký1

1 Czech Technical University in Prague, Faculty of Mechanical Engineering, Department of Process

Engineering, Technická 4, Praha 6, 160 00, email: [email protected]

Keywords: biomass, biorefinery, gasification, product gas, syngas utilization

Biomass gasification is considered one of the most promising technologies in the field of waste utilization. The presented work shows different approaches to product gas cleaning and utilization, such as fuels and chemicals synthesis or direct power generation.

One of the limiting factors for the further utilization product gas (or syngas in some cases) is the composition of the gas itself. Depending of the feedstock type and composition, gasification conditions (catalyst type, temperature etc.) and gasifier configuration the composition of the product gas can vary (examples of different compositions shown in Table 1 below, where CFB gas. stands for Circulating Fluidized Bed gasifier and EF gas. stands for Entrained Flow gasifier).

Table 1: Variety in product gas composition depending on gasification conditions (*all % are mol.) [1] technology CFB gas. CFB gas. EF gas. EF gas.

feedstock wood wood wood wood

T [°C] < 950 < 950 > 1200 > 1200

p [bar] 1 20 1 20

H2 [%]* 32 19 33 27

CO [%] 27 20 53 53

CH4 [%] 8 15 0 0

CO2 [%] 29 40 13 19

C2Hn [%] 3 5 0 0

According to other sources, more chemical

compounds (such as sulphurous compounds) can be present in the mixture as well. As many of the downstream technologies and processes that utilize the product gas use various catalysts, the product gas must be purified and catalyst poisons must be removed from the mixture. Different technologies for such purification were considered in the research (membrane processes, absorption etc.). The presented study tries to cover as wide variety of product gas compositions as possible.

Various methods of product gas utilization are compared in the study from multiple points of view - such as economical rentability or universality (ability to convert variety of input material) and other. The main approaches to product gas utilization were separation of bio-syngas (CO + H2 + ev. CO2) and its further conversion to various chemicals using Fischer-Tropsch synthesis or methanol synthesis, separation of every component gas from the mixture or CHP (combined heat and power).

Block diagrams of such technologies are presented along with PFD schemes for the most perspective ones.

Certain part of the presented study focuses on methodology of the design itself, describing the methods used for matter and energy balancing, equipment dimensioning and pricing and economical evaluating of the project.

References [1] D. Boerrigter, R. Rauch. Handbook of Biomass Gasification, Netherlands : BTG, 2005, ch. 10.

Acknowledgement This work was supported by the Ministry of Education, Youth and Sports of the Czech Republic under OP RDE grant

number CZ.02.1.01/0.0/0.0/16_019/0000753 "Research centre for low-carbon energy technologies".

51

Phthalates concentration in Anzali wetland sediments, Iran

Fatemeh Shariati1*, Mohammadjavad Mostafaloo1, Shahab Shariati2, Shayan Shariati3

1 Department of Environment, Lahijan Branch, Islamic Azad University, Lahijan, Iran,

[email protected] 2 Department of Chemistry, Rasht Branch, Islamic Azad University, Rasht, Iran 3 Department of Soil Science Engineering, University of Tehran, Karaj, Iran

Keywords: Anzali Wetland, Caspian Sea, Phthalates, Sediment.

Phthalic acid Esters (PA) are widely used as softeners in plastics industry. These compounds are now considered as ubiquitous, hard degradable and dangerous environmental contaminants [1,2]. Phthalates and their metabolites are endocrine-disrupters and harmful for human [3]. Anzali wetland has great international importance that many rivers and untreated urban and industrial wastewater enter to it. The aim of this research was to evaluate six phthalates that introduced between 100 most hazardous compounds for human by EPA [4] including dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), diethyl phthalate (DEP), dimethyl (DMP) phthalate, benzyl butyl phthalate (BBP) and Bis(2-ethyl hexyl) phthalate (DEHP) in sediments of Anzali wetland.

Figure 1: Location of sampling points in Anzali wetland

The sediment samples were taken from 22 stations with three replicates in each station in July 2015. Phthalates were separated from sediments through pressurized fluid (PFE) extraction method. For the extraction of phthalates, first 5 µg of sediment sample was poured in a conical glass vial. Then 0.5 ml acetone as dispenser solvent and 5.9 µl chlorobenzene as extraction solvent were added to sample vial. Phthalates were extracted in tiny droplets of chlorobenzene. Thereafter, the vial was centrifuged with 4000 rpm in 2 min, then 1 µl of extracted phase was taken and their measurement

were performed by gas chromatography equipped with mass spectrometer [5]. The results showed that the most polluted station is located in western part that is Nahang Roga (station 13) that enters to Caspian Sea, with total concentration of six phthalic acid esters 20.33 mg kg

-1 and

the cleanest part is Siahdarvishan (station 21) in the southeastern part with an average concentration of phthalic acid ester 0.69 mg kg

-1. The greatest

concentration of phthalic acid esters including DEHP, BBP, DBP, DIBP, DEP and DMP were 13.494, 0.236, 3.557, 3.190, 0.024 and 0.027 mg kg

-1, respectively.

Figure 2: Average phthalate concentration in sampling

points

The highest concentration belongs to DEHP, DBP and DIBP, because they have longer alkyl chains, have lower SW and high log KOW compared to DMP and DEP and hence more tendency to sediments that was in agreement with other studies [6]. Total concentrations of phthalates in stations determined by calculating the amount of phthalates in sediments and the average of all stations was 4.87 mg kg

-1 which is more than USEPA and

China standards. Also, in 77.3% of the samples, DEHP concentration was more than environmental risk limit.

References [1] M. M. Abdel Daiem, J. Rivera-Utrilla, R. Ocampo-Pérez, , J.D. Méndez-Díaz, M. Sánchez-Polo, Journal of Environmental Management 109 (2012) 164. [2] T. Deblonde, C. Cossu-Leguille, P. Hartemann, International Journal of Hygiene and Environmental Health 214 (2011) 442. [3] R. Planello, O. Herrero, J.L. Martinez-Guitarte, G. Morcillo, Aquatic Toxicology 105 (2011) 62.

[4] K. Sun, J. Jin, M. Keiluweit, M. Kleber, Z. Wang, Z, Pan et al., International Journal of Bioresource Technology 118

(2012) 120. [5] S. Net, S. Rabodonirina, R.B. Sghaier, D. Dumoulin, C. Chbib, I. Tlili, B. Ouddane, Science of the Total Environment 521 (2015) 152. [6] H. Wang, H. Liang, D. Gao, Journal of forestry research 28 (2017) 1241.

52

The use of ion exchangers for preconcentration of platinum group

metals

Jiří Sýkora1, Renata Komendová1


Environmental Protection, Purkyňova 464/118, 61200 Brno, Czech Republic,

[email protected]

Keywords: platinum, palladium, ion exchange, atomic absorption spectrometry, soil, resin, Dowex.

The aim of this research is the selection, testing and optimization of the use of ion exchangers for the preconcentration of platinum group metals. The study of the current state of the studied subject was focused on the occurrence of platinum metals (platinum and palladium) in various object of the environment, their impact on health, properties, resources and the use. We also focused on the study of preparation, pre-treatment, extraction and analytical use of ion exchangers. The experimental part deals with optimization of cation exchangers – Dowex 1-X8 (200 – 400 mesh), Dowex 1-X8 (50 -100 mesh) and Dowex 1-X10 (50 – 100 mesh) and anion exchangers – Dowex 50W-X8 (50 – 100 mesh) and Dowex 50W-X12 (50 –100 mesh). As elution solutions

were used: 0,5 mol·l-1

, 1,0 mol·l-1

hydrochlorid acid and solutions of various molarity thiourea in hydrochlorid acid. The best resin was used on nine real samples of soils from the city of Brno. These samples were taken every week for 3 months near high traffic roads.

The result was the finding and optimization of the sorption process for enrichment of platinum metal concentrations in real soil samples and their practical application for the determination of environmental levels of platinum metals.

It was found that the platinum and palladium concentrations in the soil ranged from tens of hundreds ng·g

-1 in Brno city (figure 1). The amount of platinum was

always bigger than palladium [1].

Figure 4: Amount of platinum in soil. Junction of streets - 1- Kounicova a Kotlářská; 2 - Pionýrská and Drobného; 3 - Provazníkova and Dukelská třída; 4 -Bubeníčkova and Gajdošova; 5 - Hladká and Charbulova; 6 - Dornych and Plotní; 7 - Opuštěná and Uhelná; 8 - Žabovřeská; 9 - Jezuitská and Koliště.

References [1] SÝKORA, J. Využití iontoměničů pro prekoncentraci platinových kovů. Brno: Vysoké učení technické Brně, Fakulta

chemická, 2017. 88 s. Vedoucí diplomové práce Mgr. Renata Komendová, Ph.D.

Acknowledgement This work was supported by the institution research plan No. FCH-S-18-5331 from the Ministry of Education, Youth and


0

50

100

150

200

250

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Amount of platinum in soil

26.9.2016

3.10.2016

10.10.2016

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24.10.2016

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53

Determination of antidepressants and psychoactive drugs in waste

water

Vávrová Milada, Švestková Tereza, Mravcová Ludmila, Landová Pavlína, Křivánková Zuzana, Kočnar

Michal

Brno University of Technology, Faculty of Chemistry, Purkynova 118, Brno 61200, Czech Republic

This study deals with issue of increasing consumption of pharmaceuticals and its influence on the environment. The study is divided into two parts. In the first part are analyzed pharmaceuticals from the psychoactive drugs and in the second part are analyzed antidepressants. Both groups are still widely prescribed and used by patients in Czech Republic. They are also frequently worldwide confirmed in surface and waste water in published literature. Also their negative effect for the water ecosystem is known.

In the first part were analyzed pharmaceuticals from benzodiazepine group, especially alprazolam, bromazepam, diazepam and oxazepam representatives. They are indicated for therapy of insomnia, psychiatric diseases, but also like a general anesthetics or antiepileptics.

The second presented part is focused on the antidepressants from group selective serotonin reuptake inhibitors, especially paroxetine and citalopram

representatives. Antidepressants are used for the treatment of clinical depression. They are also used to treat a number of other conditions as obsessive compulsive disorder, post-traumatic stress disorder or for people with long-term (chronic) pain.

The target of this study was optimize the method for isolation from complex matrix followed by optimized chromatographic detection. There was also evaluated the removal efficiency from wastewater treatment plant (WWTP) located in Brno-Modřice and their hazard level for water ecosystem related to the presence of pharmaceuticals residues wastewater matrices due to insufficient treatment process of WWTP.

The solid-phase extraction (SPE) was used for isolation all analytes from wastewater. The ultra-high performance liquid chromatography coupled with diode array detector (UHPLC-DAD) was used for identification and quantification.

Acknowledgement This work was supported by Ministry of Education, Youth and Sports of Czech Republic, grant No. FCH-S-18-5331.

54

Separation of air pollutants using different types of scrubbers

Jaroslav Vlasák 1, Tomáš Svěrák1, Lukáš Drevený1, Josef Kalivoda1

1 Faculty of Chemistry, Brno University of Technology, Institute of materials science, Brno 612 00,

Purkyňova 464/118, Czech Republic, [email protected]

Keywords: wet scrubber, absorption, gas, mass exchangers,

The limitation of emissions of industrial gaseous pollutants can be ensured in various ways. In some cases, it is possible to reduce emissions by adjusting the production process by using raw material or fuel with a low content of substances from which the pollutants arise or by reducing the content of these substances in the raw material or by the fueling processes. More frequent separation of harmful gas components from tail gases or chemical catalytic or thermal decomposition to the resulting harmless substances is necessary. The processes as separation, adsorption, condensation, oxidation and reduction, combustion (thermal oxidation) and catalytic oxidation are most often used for the separation of gaseous industrial pollutants or for their reduction. The choice of the separation process generally depends on the chemical and physical properties of the separated substance and on the technological conditions in which the pollutant originates or is discharged into the atmosphere. An important consideration is the concentration of pollutants in the carrier gas, its total volume and temperature, as well as the particulate matter content. The choice also affects whether the separating device is to be operated continuously or discontinuously, and on the possibility of using trapped substances, etc. The gaseous exhalate cleaning technique is still under strong development. However, it provides many possibilities for gaseous air pollutants to be captured and disposed of [1,3].

Industrial cleaning of gases, the so-called scrubbing in some cases, is a basic chemical-engineering problem, which aims to capture gas components from the gas mixture. Different physicochemical processes and biological processes are part of this issue and one of these processes is absorption. In the chemical industry, absorption is widely used, especially in the production of basic raw materials in the chemical industry, such as sulfuric acid, nitric acid, nitrate production by alkaline absorption, or in the food industry in the production of carbonated beverages and other applications [2].

There are presented individual types of mass exchangers and specific type of wet scrubber for future measurement, which is designed as a one-stage cleaning system for the removal of gaseous pollutants of airs mainly. The necessary contacts of the gaseous and liquid phases are mediated in the scrubber head, where the liquid is dispersed through the spiral nozzle into a thin spiral fluid film which is subsequently pulled into individual droplets and the gaseous phase is passing through the fluid film.

Our work tries to find the optimum scrubber regimes in the conditions of separation of the gaseous pollutants contained in the air into the spraying liquid via a chemisorption process on a pilot-plant liquid scrubber.

Figure 1: Wet scrubber

References [1] VEJVODA J., MACHAČA P., BURYAN P.Technologie ochrany ovzduší a čištění odpadních plynů. (2003) 226. [2] Kalivoda J. Odstraňování plynných polutantů ze vzdušnin na poloprovozní pračce (2017) 216. Doctoral thesis. Brno University of Technology, Faculty of Chemistry. Supervisor Prof. Ing. Tomáš Svěrák CSc. [3] Zarzycki R., Chacuk A. Absorption Fundamentals (2013) 659.

Acknowledgement This work was supported by Faculty of chemistry BUT under project No. FCH-S-18-5194.

55

Ecotoxicity evaluation of fire extinguishing agents

Helena Zlámalová Gargošová1, Barbora Jabandžievová1


Environmental Protection, Purkyňova 118, 612 00 Brno, Czech Republic; [email protected]

Keywords: ecotoxicity test, fire extinguishing agents, contact tests

Fires have a negative impact on the environment not only through the production of many toxic products like PAHs, PCDDs, PCDFS, CO etc. but also through application of modern fire extinguishing agents, especially foams based on surfactants. The results of ecotoxicological tests of fire-fighting foams which we obtained in our previous study [1,2] should arise attention because the fire-fighting foam based agents exhibited relatively high ecotoxicity.

The aim of our study was to continue in ecotoxicity evaluation of the most used extinguishing agents (FEAs) which are often applied in fire cases by Fire Rescue Unit in South Moravian region, Czech Republic. The other reason are rare information about hazard to the environment which should be included in safety data sheet (MSMD); if they are present they describe only hazard to the aquatic ecosystem but not to terrestrial one, especially to soil ecosystem.

For the above mentioned reasons ecotoxicity of solid wetting agent based on foam TS Turbo (with fluorinated surfactants), TS ECO (without fluorinated surfactants) and ABC FAVORIT 111 (fire - extinguishing powder based on ammonium salts of phosphates and sulphates) were

tested. In respect to the fact, that residues of these agents could enter not only aquatic but also terrestrial ecosystem the above mentioned fire extinguishing agents were tested not only in aquatic arrangement (via crustacean Daphnia magna and algae Scenedesmus quadricauda) but also in contact/terrestrial arrangement (via representative of soil edaphone as springtail Folsomia candida and earthworm Eisenia fetida, and representative of higher plants lettuce Lactuca sativa). Results of our test indicate that higher sensitivity from aquatic testing organisms exhibits crustacean D. magna. Value of 48hEC50 calculated for TS Turbo and TS ECO were in hundredths of grams per liter but values for ABC FAVORIT were in tenths of grams per liter indicating its higher toxicity in comparison with toxicity for S. subspicatus, where the values of 72hIC50 were one or two orders higher. Toxicity of tested fire extinguishing agents to soil organisms was similar and ecotoxicological values were in units of grams per kilogram of soil. From all obtained results we can conclude that the lowest ecotoxicity exhibited the ABC FAVORIT – powder.

References [1] Š. Hřibová, H. Zlámalová Gargošová, M. Vávrová, Fresenius Environmental Bulletin 12 (2014) 3029. [2] Š. Hřibová, H. Zlámalová Gargošová, M. Vávrová, Interdisciplinary Toxicology 7 (2015) 177.

Acknowledgement This work was supported by Project No. FCH-S-18-5331.

56

Czech and Slovak Food Science Meeting

57

Lignans in foods and food fortification using 7-HMR

Josef Balík1, Pavel Híc1, Jana Kulichová1, Jan Tříska2, Naděžda Vrchotová2, Milan Houška3

1 Mendel University in Brno, Faculty of Horticulture in Lednice, Lednice 691 44, Valtická 337,

[email protected] 2 Global Change Research Institute, CAS, Brno, Czech Republic 3 Food Research Institute Prague, Prague, Czech Republic

Keywords: lignan, food, hydroxymatairesinol, spruce knots, lignan extraction

Lignans belong among the broad group of plant phenols. In terms of structure, lignans consist of two phenyl-propane units that are connected via the central beta carbons of either of the side chains. As secondary metabolites of vascular plants, lignans perform a number of functions in plants [1]. The increased interest in lignans is based primarily on their use in pharmacy and nutrition. A report was published by Slanina [2] and provides a good overview of the health effects of lignans.

Lignans are most frequently found in wood and bark of trees, as well as in roots, leaves, flowers, fruits and seeds of plants. Lignans are found in their free form as aglycones, particularly in woody plants; in the case of agricultural products, they are also bound to a wide group of carbohydrates. Agricultural and food products chiefly contain matairesinol, secoisolariciresinol, lariciresinol, and pinoresinol. Overall, the highest lignan concentrations in the raw materials used for food production were measured in the seeds of flax (predominantly oligomers of secoisolariciresinol diglucoside) and sesame (predominantly sesamin). Other important sources of lignans in our diet include whole-grain cereals, leguminous crops and other types of vegetables, certain types of fruit and berries, nuts, wine (particularly red wine), tea and coffee. The list of lignans in foodstuffs is constantly expanding; lignans also fill the emerging databases that inform on individual types of the group and their concentrations.

A group of Finnish scientists published discovery of what is likely the richest natural source of lignans. Holmbom et al. [1] found that the mass fraction of lignans contained in knots of trees was an average of 5 % - 10 %. In addition, knots of Norway spruce (Picea abies) contained up to 6 % - 29 % of lignans; of these,

7-hydroxymatairesinol (HMR) was the most

represented lignan forming up to 70 % - 85 % of total lignan content.

Normally, lignans are sourced by extraction from plant materials - including ground knots of spruce - using polar solvents (such as ethanol and acetone) or their mixtures with water, after removing the lipophilic substances by extraction using non-polar solvents, e.g. hexane [4]. Use of water alone as a solvent for knot extraction is a prospective method; it is seen as a green technology in which no organic solvents are used, thus the resulting substance is more acceptable for the consumer. To extract lignans, the technology patented by the authors and their collaborators [5] makes use of hot water in which resins and other non-polar substances are insoluble. The subsequent part of HMR concentration and purification makes use of lyophilisation and solubility of HMR in food-grade alcohol.

The application of lignans in food was the subject of work of the team of the authors along with other co-investigators as part of the research project entitled “Lignan extraction from wood mass and use in food supplements with significant biological effects”. Various forms of lignans (e.g. spruce knot chips, spruce knot alcoholic extract and so-called green spruce knot extract) were tested by adding them into specific beverages and foodstuffs (grape musts, white/red wine, beer, fruit/vegetable spreads and chocolate); subsequently, selected characteristics of the materials were evaluated, particularly the antioxidant activity, total polyphenols, and sensory acceptability. The most of the procedures described below were patented or utility models were granted for them.

References [1] J. Harmatha, Chemické listy 99 (2005) 622-632. [2] J. Slanina, Chemické listy 94 (2000) 111-116. [3] B. Holmbom at al., Phytochemistry Reviews 2 (2003) 331-340. [4] S.M. Willför et al., Journal of Agricultural and Food Chemistry, 51 (2003) 7600-7606. [5] P. Híc et al., Úřad průmyslového vlastnictví Pat. No. 306 700 (2017).

Acknowledgement This research was supported by research project QJ1210258 financed by the Ministry of Agriculture of the Czech

Republic.

58

DNA binding properties of p53 mutant R249S protein induced by

exposure to aflatoxin in food

Václav Brázda1,2, Natália Vadovičová1, Eva B. Jagelská2, Jan Coufal2,

1 Faculty of Chemistry, Brno University of Technology, Purkynova 118, 612 00 Brno, Czech Republic,

[email protected] 2 Czech Academy of Sciences, Institute of Biophysics, Královopolská 135, Brno, Czech Republic

Keywords: p53, mutant, aflatoxin, protein-DNA binding

Aflatoxins are toxic metabolites produced mainly by Aspergillus flavus, Aspergillus parasiticus or Aspergillus nominus. Aflatoxins are found in a wide range of foods and crops. The most common are in maize, rice and wheat. Aflatoxins may also be present in peanuts, almonds, figs, milk, dairy products, eggs or meat products, especially when stored poorly.

Molecular epidemiology shows that carcinogens leave fingerprints leading to mutations in genes frequently altered in cancer. It has been demonstrated that chronic infection with hepatitis B virus (HBV) and exposure to aflatoxin B1 (AFB1) induces p53 mutations in hepatocellular carcinoma (HCC) tissue. After AFB1 exposure, mutation of p53 gene is the most frequently occurring in codon 249 (R249S) in exon 7 (G to T transversion). This mutation is so frequent that it can serve as a mutation marker induced by AFB1 mutagen.

AFB1 is classified as a group I carcinogen in humans by IARC. Recent studies have suggested that oncogenes are critical molecular targets for AFB1, and AFB1 causes characteristic genetic changes in the p53 tumor suppressor gene and ras protooncogene.

Missense mutations in the DNA-binding core domain of the tumor suppressor protein p53 are frequent in cancer. Many of them result in loss of native structure. The mutation R249S is one of the six most common cancer-associated p53 mutations. In our study we compare p53 wt and mutant proteins and its DNA binding affinity in various conditions. Interestingly neither ability to bind to DNA nor conformational analysis accurately defines the transcriptional activity of human tumor-derived p53 mutant proteins.

References [1] V. Brazda, P. Muller, K. Brozkova, and B. Vojtesek: “Restoring wild-type conformation and DNA-binding activity of

mutant p53 is insufficient for restoration of transcriptional activity.” Biochem. Biophys. Res. Commun. vol. 351, no. 2, pp. 499–506, 2006.

[2] E.B. Jagelská, H. Pivoňková, M. Fojta, and V. Brázda: “The potential of the cruciform structure formation as an important factor influencing p53 sequence-specific binding to natural DNA targets.” Biochem. Biophys. Res. Commun. vol. 391, no. 3, pp. 1409–1414, 2010.

[3] V. Brázda and J. Coufal: “Recognition of local DNA structures by p53 protein.” Int. J. Mol. Sci. vol. 18, no. 2, pp. 375, 2017.

[4] V. Brázda, J. Čechová, M. Battistin, J. Coufal, E.B. Jagelská, I. Raimondi, and A. Inga: “The structure formed by inverted repeats in p53 response elements determines the transactivation activity of p53 protein.” Biochem. Biophys. Res. Commun. vol. 483, no. 1, pp. 516–521, 2017.

Acknowledgement This work was supported by project FCH-S-18-5334 and by the Grant Agency of the Czech Republic (18-15548S).

59

Analysis of yeast exoproducts related to antifungal activity of

Metschnikowia pulcherrima

Emília Breierová, Dominika Šoltésová, Barbora Stratilová and Vlasta Sasinková

Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 38 Bratislava, Slovak

Republic

Keywords: Metschnikowia pulcherrima, pulcherrimin, biocontrol yeast, yeast pathogens

The ecological distribution of the yeast species Metschnikowia pulcherrima is broad over the world and includes flowers, fruits and also other parts of plants. The role of the yeast species M. pulcherrima in the ecosystem is quite important. The carriers of this species are different insects that visit plants and serve as natural vectors for distribution of different yeast species. The antagonistic properties of M. pulcherrima show great potential to become biological control agents of natural origin against a wide range of saprophytic and pathogenic microorganisms [1,2]. Four strains of M. pulcherrima and 1 strain of M. andauensis were evaluated for the antimicrobial activity against the yeast strains belonging to Cryptococcus neoformans, Candida albicans, Candida glabrata, Candida parapsilosis and Candida dubliniensis. All M. pulcherrima strains (CCY 29-2-145, CCY 29-2-147, and CCY 29-2-149), M. andauensis (CCY 29-2-129) and pulcherrimin mixtures isolated showed antifungal activity. 4 3 2 1

Figure 1: Killer activity against Candida albicans CCY 29-3-164. 1-above 670kDa, 2-670 -10 kDa, 3- 5-10 kDa and 4- below 5kDa.

We found differences in the colour of pulcherrimin, in the power of antifungal activity and also in the production of this pigment by yeasts. Results showed both, different inter-generic and intrageneric responses of the pathogenic yeasts tested to the antimicrobial action of M. pulcherrima strains. The reaction of the strain Candida albicans, which is

resistant to azole compounds, was very promising,

because both pulcherrimin and the native form of it

exhibited a significant antifungal effect. Simple isolation

of pulcherrimin gives the possibility to use this substance

as an effective antimicrobial preparation.

We found that pulcherrimin isolates are composed of

exopolysaccharides, peptides and pulcherrimin. Killer

activity against Candida albicans CCY 29-3-164 was

verified by Purification- Chromatography- (Superdex 75

HR 10/30) of pulcherrimin compounds. The active

ingredient of the mixture isolated was found in molecules

of over 670 kDa (the majority formed pulcherrimin

pigment and 5-10 kDa was not related to the pigment).

All strains of M. pulcherrima and M. andauensis as well as pulcherrimin mixtures showed antifungal activity. The antimicrobial activity of M. pulcherrima is exhibited

not only by proteinaceous compounds, such as killer

phenomenon, but also by pulcherriminic acid (the

precursor of pulcherrimin pigment) that depletes iron

present in the medium, making it not available to the

other yeasts, which was confirmed by VTIR spectroscopy.

References [1] L. Oro, M. Ciani and F. Comitini, 2014 , J. Appl. Microbiol, 116, 1209-1217 [2] Sipiczki M., 2006. Metschnikowia strains isolated from botrytized grapes antagonize fungal and bacterial growth by iron depletion, Applied and Environmental Microbiology 72, 6716-6724

Acknowledgement This work was supported by grants from the Slovak Grant Agency of Science (VEGA 2/0017/18 and 2/0058/16) and the

Slovak Research and Developmental Agency (APVV-15-0744). .

60

Positioin of Food Fraud Prevention and Food Defence in Food Safety

Management Systems

František Buňka, Michaela Černíková

Department of Food Technology, Faculty of Technology, Tomas Bata University in Zlin, nam. T. G.

Masaryka 5555, 760 01 Zlín, Czech Republic

The aim of the presentation is explaining the new role of food fraud prevention and food defence in FSMS (Food Safety Management System). The content will be focused on application in area of schemes and standards

recognized by GFSI (Global Food Safety Initiative). The special attention will be paid to Food Safety System Certification (FSSC22000).

61

Biotechnological Preparation of Functional Cereals-Based Food and

Feed

Milan Čertík1, Tatiana Klempová1, Ondrej Slaný1, Miroslav Janák1, Slavomír Marcinčák2

1 Institute of Biotechnology, Faculty of Chemical and Food Technology, Slovak University of

Technology in Bratislava, Radlinského 9, 812 37 Bratislava, Slovak Republic, [email protected] 2 Department of Food Hygiene and Technology, University of Veterinary Medicine and Pharmacy in

Košice, Komenského 73, 041 81 Košice, Slovak Republic

Keywords: functional cereal, biotechnology, fungal solid-state fermentation

Functional food/feed can be characterized as a nourishment that contains one or more ingredients to provide a positive wellbeing and health benefit beyond basic nutrition. Cereals as one of the main component in human diet are quite low in fats and are lacking or limiting in some essential lipophilic compounds such as polyunsaturated fatty acids (PUFAs) and carotenoids. However, cereals could be considered as useful sources of functional foods/feed if their biochemical composition is modified appropriately.

One of the most promising natural process to reach this goal is based on the solid-state fermentation (SSF) where lower filamentous fungi (Thamnidium sp., Cunninghamella sp., Mucor sp., Umbelopsis sp., Mortierella sp.) effectively utilize and enrich cereal materials with biologically active compounds (PUFAs, carotenoids, ergosterol, coenzyme Q10, glycolipids, dietary fibres and various enzymes) [1]. Fungi also improve content of dry matter, proteins and ash in

fermented cereals. Numbers of low-cost cereal byproduct have been screened and cultivation conditions have been optimized to reach a maximum yield of bioactive compounds in fermented bioproduct. Depends on the fungal strain, a range of cereal-based bioproducts enriched with PUFAs (up to 2.4% gamma-linolenic acid, 4.2% arachidonic acid, 2.1% dihomo-gamma linolenic acid, 2.3% eicosapentaenoic acid) and pigments (0.26% beta-carotene) have been prepared [2] and successfully employed for making cereal goods (e.g. rolls, bread and pasta) [3] and tested as a feed additive for animal diet (chicken, calves, artificial rumen) [4]. These microbial-derived bioproducts with improved nutritional and functional properties should be generally recognized as safe (GRAS) and may open novel prospects for the market of functional microbial-based food and feed supplements.

References [1] M. Čertík, T. Klempová, Materials Science Forum 851 (2016) 8-13. [2] M. Čertík, T. Klempová, L. Guothová, D. Mihálik, J. Kraic, European Journal of Lipid Science and Technology 115

(2013) 1247-1256. [3] T. Klempová, J. Janštová, S. Gavurníková, M. Havrlentová, M. Čertík, Materials Science Forum 851 (2016) 14-19. [4] M. Čertík, T. Klempová, D. Jalč, Z. Váradyová, S. Marcinčák, in: Food Lipids - Chemistry, Nutrition, and

Biotechnology, C.C. Akoh (Ed.), Boca Raton (FL, USA), CRC Press with Taylor & Francis, 2017, pp 765-778.

Acknowledgement The work was supported by grants VEGA 1/0574/15 (Slovak Ministry of Education, Science, Research and Sport) and

APVV-14-0397 (Slovak Research and Development Agency).

62

Validation of diffusive gradient in thin films technique for

determination of mercury in fish sauce

Pavel Diviš 1, Marek Reichstädter1, Aneta Habartová1 and Jakub Kříkala1

1 Brno University of Technology, Faculty of chemistry, Department of Food Chemistry and

Biotechnology, Purkyňova 118, Brno 612 00, Czech Republic, [email protected]

Keywords: mercury, fish sauce, DGT, atomic spectrometry

Diffusive gradient in thin films technique (DGT) has become a routine tool for speciation analysis of metals in natural waters, sediments and soils [1]. Since its introduction in 1994, more application possibilities appeared [2,3]. At present, more than 50 elements can be analyzed by DGT, and studies have also been carried out to explore the use of this technique for mercury determination [4,5].

In this work the possibility to use the DGT technique for determination of mercury in fish sauces was studied. The preparation of a new sorption gel has been tested. After optimization of sorption gel preparation, this new gel was inserted into the plastic DGT sampling unit together with agarose diffusive gel and cellulose filter membrane (Figure 1) and correct function of DGT technique was tested in model solution containing 20

g.l-1

of mercury and 0.01 mol.l-1

NaCl. Mass of mercury accumulated in sorption gel and mercury concentration in model solution was analyzed by AAS technique using AMA-254 instrument (Altec, Czech Republic).

Figure 1: Schematic representation of DGT sampling unit

Mass of mercury accumulated in the sorption gel linearly increased with the increasing exposure time, which confirms the correct function of DGT (Figure 2). The repeatability of the measurement expressed as the relative standard deviation was 8 %. As the fish sauce is food with high salt content, the effect of the salt content in the solution on the DGT measurement has been tested. Salt concentration up to 50 g.l

-1 did not affect the correct

function of DGT technique. The effective diffusion coefficient under the tested conditions was calculated to be 6.23 x 10

-6 cm

2.s

-1.

Figure 2: Accumulation of mercury in sorption gel during different exposition time

Finally the DGT technique was used for analysis of mercury in fish sauce sample. The determination showed the advantage of the DGT technique to separate the analyte from the complex matrix and to detect very low concentrations of mercury.

References [1] P. Diviš, H. Dočekalová, V. Řezáčová, Chem. Listy 97 (2003) 1184. [2] H. Chen, L.W. Guo, M.H. Zhang, J.L. Gu, K.L. Zhong, L. Bo, J.R. Li, Food Chem, 165 (2014) 9. [3] A. Pelfrene, C. Waterlot, Douay F., Anal. Chim Acta, 699 (2011) 177. [4] O.A. Garmo, O. Royset, E. Steiness, T.P. Flaten, Anal Chem, 75 (2003) 3573. [5] H. Dočekalová, P. Diviš, Talanta, 65 (2005) 1144.

Acknowledgement This work was supported by project FCH-S-18-5334 funded by Ministry of Education, Youth and Sports of Czech

Republic

63

Diversity of Yeasts Colonizing Aboveground Plant Organs of Fruit

Trees and the Soil Related to these Trees

Hana Dudášová, Renáta Vadkertiová

Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 38 Bratislava,

Slovak Republic

Keywords: blossoms, diversity, fruits, leaves, soil, yeasts, yeast-like organisms

Yeasts form significant and diverse part of the phyllosphere microbiota. The diversity and density of yeasts in this environment depend on various factors such as geographical locality, climatic conditions, season, plant species, and plant organs. Yeasts are also present in high amounts in the soil close to flowering plants that bear fruits [1, 2] because of the nourishment they provide for yeast consortia.

Presented study is focused on the diversity of yeasts and yeast-like organisms associated with fully opened blossoms, matured fruits [3], leaves [4], and soil adjacent to fruit trees. Samples were harvested in two localities of southwest Slovakia during two consecutive years.

Diversity of yeasts inhabiting fruits (data show % of samples positive for an individual group of yeasts).

Majority of the species isolated was similar for all aboveground plant organs; their frequency differed within individual plant organs and sampling periods. Leaves harboured mainly Aureobasidium and the species of the former Cryptococcus, which produce compounds

such as pigments and exopolysaccharides which protect cells from unfavourable conditions. Fuits were inhabited mainly by yeasts belonging to the genera Pichia, Hanseniaspora, Metschnikowia which are known to produce aroma compounds. In the soil, pedobiont yeasts (Barnettozyma californica, Schanniomyces capriotti, Cyberlindnera misumaiensis, Tausonia pullulans, Apiotrichum spp., Trichosporon spp.) formed the most significant part of the yeast microbiota. Fruit-related yeast species present in soil reflected diversity of yeast species associated with aboveground plant organs.

Diversity of yeasts isolated from leaves ((data show % of samples positive for an individual group of yeasts).

Some rare species were also found. Candida boidinii

was isolated only from apple tree blossoms, Pichia fermentans from fruits, while Wickerhamomyces anomalus, Meyerozyma guilliermondii, Papiliotrema flavescens occured on leaves of apple tree. Filobasidium stepposum, Goffeauzyma gastrica and Candida norvegica were isolated from the soil adjacent to fruit trees.

References [1] A. Botha, Soil Biology and Biochemistry 43(1) (2011) 18. [2] H.J. Phaff, in Methods in Enzymology, E.F. Neufeld, V. Ginsburg (Eds.), New York, 1966, p. 641 [3] R. Vadkertiová, J. Molnárová, D. Vránová, E. Sláviková, Canadian journal of Microbiology 58 (2012) 1344 [4] E. Sláviková, R. Vadkertiová, D. Vránová, Annals of microbiology 59(3) (2009) 419

Acknowledgement This work was supported by grants from the Slovak Research and Development Agency (APVV-0744-15) and VEGA No.

2/0017/18

A. pullulans

Basidiomycet.

M. pulcherrima

Pichia sp.

S. cerevisiae

H. uvarum

G. geotrichum

S. crataegensis

0 10 20 30 40

05

101520253035

64

Comparison of sensitivity of DNA biochip and Real Time PCR for

pork DNA in meat products

Zuzana Drdolová1, Jozef Golian2

1 Ing. Zuzana Drdolova, Slovak University of Agriculture, Faculty of Biotechnology and Food

Sciences, Department of Hygiene and Food Safety, Tr. A. Hlinku 2, 949 76 Nitra,

Slovakia, E-mail: [email protected] 2 prof. Ing. Jozef Golian, Dr., Slovak University of Agriculture, Faculty of Biotechnology and Food

Sciences, Department of Hygiene and Food Safety, Tr. A. Hlinku 2, 949 76 Nitra, Slovakia, E-mail:

[email protected]

Keywords: DNA biochip, pork, meat, Real Time PCR

Determination of animal species in the meat and meat products is one of the interest of food science, it is also important for consumer rights and food safety. Increasing world population has also remarkably impacted the demand for meat and meat products. With the growing globalization of the food industry, adulteration has become a key food safety and food value issue within the supply chain. In fact, food products may be adulterated, and highly valuable species substituted, partially or entirely, with similar but cheaper ones [1].

Authentication of food product ingredients by food control agencies relies on analytical laboratory methods for animal species identification. Such methods must be validated if their results are to be used as acceptable evidence in a court of law [2].

The aim of the study was comparison of sensitivity of DNA biochip and Real Time PCR. Pork DNA was detected in meat mixtures, meat products. Five meat mixtures containing beef with varying percentage of pork (0,1 %, 0,5%, 1%, 5% and 10%) and 25 commercial food products, were analyzed using DNA biochip and RT-PCR to determine the presence of pork DNA. Pork DNA standard curves and cycle threshold (Ct) values were used for quantification. The detection limit for pork DNA in the mixtures were 0.23 ng/μl respectively. The LCD Array showed high specificity and high sensitivity and it appeared to be robust and repeatable. As such, it provides a useful tool for detecting common adulterants in food items of animal origin. It was found that the results obtained by DNA biochip and Real Time PCR assays were identical with each other, and both methods should extensively be promoted for the detection of animal species in the meat and meat products.

Table 1: Compared results between DNA microarray and Real Time PCR

Description of

Sample

Chipron LCD Array Meat 5.0 Kit

innuDETECT PCR Real-Time Kit

Beef Pork Beef Pork

10 % Pork, 90 % Beef

5 % Pork,

95 % Beef

1% Pork, 99 % Beef

0,5% Pork, 99,5 % Beef

0,1% Pork,

99,9 % Beef

+

+ + +

+

+ + +

+

+ + +

+

+ + +

+

+ + +

No quantitative potential was confirmed in the DNA

biochip. The results obtained by DNA biochip and Real Time PCR were the same indicated that 11 out of 25 samples (44%) were labelled incorrectly, and adulteration was made in contrary to the notifications on the label.

The validation process of the MEAT 5.0 LCD biochip, carried out according to SWGDAM guidelines (SWGDAM, 2012), showed that the kit has high specificity and sensitivity, making it a reliable method to detect several animal species simultaneously, also for food forensic analysis.

References [1] Ch. Beltramo, M. Riina, S. Colussi et al., Food Control 78 (2017) 366. [2] H. Ozpinar, G. Tezmen, I. Gorke et al.,Kafkas Univ Vet Derg 19 (2013) 245.

Acknowledgement This work was supported by grant VEGA No. 1/0276/18.

65

Maldi TOF Analysis For Verification of Collection Yeasts And

Classification of New Isolates

Ágnes Horváthová1, Natália Čurillová2, Monika Vadkertiová3, Laura Vyšehradská4, Ivana Márová2,

Hana Dudášová1, Barbora Stratilová1,5

1 Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava,

Slovakia 2 Institute of Food Chemistry and Biotechnology, Faculty of Chemistry, Brno University of

Technology, Purkyňova 118, CZ-61200 Brno, Czech Republic 3 Wissenschaftszentrum Weihenstephan für Ernährung, Landnutzung und Umwelt, Technische

Universität München, DE-85354 Freising, Deutschland 4 Institute of Biochemistry and Microbiology, Faculty of Chemistry and Food Technology, Slovak

Technical University in Bratislava, Radlinského 9, SK-81237 Bratislava, Slovakia 5 Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius

University in Bratislava, SK-842 15 Bratislava, Slovak Republic

Keywords: Biotyping; CCY; classification; MALDI TOF; verification; yeasts

Mass spectrometry - based classification of microorganisms (MALDI biotyping) is one of powerful methods used at present days in identification of both fungi and bacteria. This method is quick, relatively cheap and requires only small amount of biological material. However, it demands high quality reference spectra and correct identification of microorganisms which provide these spectra. Identification of reference strains is based on molecular biology methods as D1/D2 LSU (26S) rRNA and/or ITS1, ITS2 domain sequencing. The “fingerprint” of a sample and reference intracellular proteins, typical of individual species or even variety, is compared to each other, using programs as MALDI Biotyper (Bruker), which gives the final probability of their identity.

One hundred and thirty-two yeast strains: 1) isolates from various environment in previous studies and identified on the base of their morphological and physiological properties (deposited in the Culture Collection of Yeasts - CCY, Institute of Chemistry of SAS) and 2) new isolates, were subjected to this work.

Two cultivation media and three methods of sample preparation were utilized. The best results were reached with YPD medium, ethanol wash of culture and sinapic acid/ferulic acid (3/1) matrix for measurement (success rate of identification about 91 %).

In total, 24 yeast species - Barnettozyma californica, Candida bombi, Candida cretensis, Candida glabrata, Candida kruisii, Cystofilobasidium infirmominiatum, Cystofilobasidium macerans, Hanseniaspora guilliermondii, Hanseniaspora uvarum, Metschnikowia fructicola, Metschnikowia pulcherrima, Metschnikowia reukaufii, Meyerozyma guillermondii, Papiliotrema flavescens, Pichia guilliermondii, Pichia

membranifaciens, Rhodotorula dairenensis, Rhodotorula mucilaginosa, Rhodotorula spp., Saccharomyces cerevisiae, Solicoccozyma aeria, Sporidiobolus metaroseus, Sporidiobolus pararoseus and Sporidiobolus salmonicolor were identified (Figure 1). We suggest sequencing of eight percent of samples (10 strains), because their spectra have not corresponded any references.

Figure 1: The relative representation of strains in evaluated sample. Total number of strains 132.

In conclusion, MS biotyping is a promising method for identification of a high number of strains of the same species. It can spare time and money up to 92%, in comparison to the molecular biology methods.

Acknowledgement This work was supported by grants from the Slovak Grant Agency of Science (VEGA 2/0017/18 and 2/0058/16) and the Slovak Research and Developmental Agency (APVV-15-0744).

http://www.wzw.tum.de/

66

Effects of conventional heating on fatty acids profile of virgin and

refined olive oil

Dani Dordevic1, Lucia Hodulová1, Simona Jančíková1, Sanja Ćavar Zeljković2,3

1 Department of Plant Origin Foodstuffs Hygiene and Technology, Faculty of Veterinary Hygiene and

Ecology, University of Veterinary and Pharmaceutical sciences Brno, Czech Republic 2 Centre of Region Haná for Biotechnological and Agricultural Research, Central Laboratories and

Research Support, Faculty of Science, Palacky University, Olomouc, Czech Republic 3 Centre of the Region Haná for Biotechnological and Agricultural Research, Department of Genetic

Resources for Vegetables, Medicinal and Special Plants, Crop Research Institute, Olomouc, Czech

Republic

Keywords: olive oil, home heating process, fatty acid profile.

Olive oil is well distinguishable among other edible oils due to its high content of monounsaturated fatty acids especially oleic acid [1].

The aim of the study was to overview the influence of the most often home heating process on fatty acid profile of retail bought different types of olive oils.

The total number of samples (n=18) used for the experiment consisted out of olive oil mixtures (EVOO+ROO) (refined olive oil + extra virgin olive oil) (n=4) and multivariate extra virgin olive oil (EVOO) (olive oil bought in retail markets in the Czech Republic, originating from Spain and Greece) (n=14). Olive oil samples were heated at 180 °C and 220 °C. At each temperature regime, samples were heated during 10 minutes, 3 x repeatedly. Olive oil samples undergone fatty acids profile analyses. Fatty acids profile was carried out by the usage of gas chromatography–mass spectrometry (GC-MC – Agilent 7890 apparatus). The results were statistically processed by SPSS statistical software.

Table 1: Fatty acid profile changes in EVOO

According to gained results can be concluded that heating processes affects fatty acid profile significantly (p<0.05), especially oleic acid contents were reduced

(control before 180 °C: 42.26 ± 3.39%; after 3 x 10 minutes heating: 36.03 ± 2.24%). It should be emphasized that changes were observed both in extra virgin and refined olive oils. Though, reduction was more significant at 220 °C (Table 1 and 2). These results are in accordance with the finding that extra virgin olive oil heated at 190 °C was more stable due to the presence of antioxidants, especially carotenoids [3].

Table 2: Fatty acid profile changes in olive oil (EVOO+ROO)

Olive oil is characterized as the most stable vegetable edible oil to oxidative processes due to the presence of antioxidants and small amount of polyunsaturated fatty acids. It has been also indicated that literature data about fatty acids profile changes of commercial olive oils during home frying is scarce. The changes of fatty acid profile during heating occur due to a series of radical reaction that oxidized the double bonds carbons in fatty acids [2].

From consumers’ perspectives, the research confirmed thesis that virgin olive oil possess lower stability toward higher temperatures (220 °C) and should be used in cold meal preparation. Another aspect of the research emphasized lower quality of virgin olive oil in the market of the Czech Republic.

References [1] Khemakhem, I., Yaiche, C., Ayadi, M. A., Bouaziz, M. Impact of aromatization by Citrus limetta and Citrus sinensis

peels on olive oil quality, chemical composition and heat stability. Journal of the American Oil Chemists' Society, 2015, 92(5), 701-708.

[2] Carmona, M. Á., Lafont, F., Jiménez‐Sanchidrián, C., Ruiz, J. R. Raman spectroscopy study of edible oils and determination of the oxidative stability at frying temperatures. European journal of lipid science and technology, 2014, 116, 1451-1456.

[3] Yanishlieva, N. V., Aitzetmüller, K., Raneva, V. β‐Carotene and lipid oxidation. European Journal of Lipid Science and Technology, (1998), 100(10), 444-462.

Virgin olive oil 220 C

SFA Control 1st

frying 2st

frying 3st

frying

Ʃ SFA 33.77 ± 4.14 29.13 ± 5.74 30.15 ± 7.60 28.31 ± 5.26

C 18:1 43.15 ± 3.87a 9.37 ± 5.67b 7.22 ± 2.96c 7.45 ±5.79c

Ʃ MUFA 54.90 ± 4.38a 23.79 ± 8.12b 22.79 ± 3.80b 19.85 ± 5.68b

Ʃ PUFA 4.06 ± 1.25a 3.85 ± 2.01ab 2.33 ± 1.47b 2.34 ± 1.37b

Rafinated olive oil 220 C

SFA Control 1st frying 2st frying 3st frying

ƩSFA 31.70 ± 3.12 25.53 ± 8.47 31.89 ± 8.71 22.67 ± 7.20

C 18:1 42.26 ± 3.39a 29.56 ± 3.33a 7.14 ± 2.06b 6.51 ± 0.00c

ƩMUFA 56.73a ± 2.34 45.73 ± 3.08a 16.99 ± 5.50a 16.79 ± 2.02a

ƩPUFA 5.49 ± 0.17a 3.10 ± 0.29ab 2.38 ± 1.32b 1.22 ± 1.17b

67

The effect of final heating on the concentration of phthalic acid

esters in sous-vide products

Marcela Jandlová1, Alžbeta Jarošová2, Josef Kameník3

1 Mendel University in Brno, Department of Food Technology, Faculty of AgriSciences, Zemědělska

1, 613 00 Brno, Czech Republic, [email protected]

2 Mendel University in Brno, Department of Food Technology, Faculty of AgriSciences, Zemědělska

1, 613 00 Brno, Czech Republic 3 University of Veterinary and Pharmaceutical Sciences Brno, Department of Gastronomy, Faculty

of Veterinary Hygiene and Ecology Palackého 1946/1, 612 42 Brno

Keywords: dibutylphtalate, di-(2-ethylhexyl)phthalate, wrapping, meat, water, sous-vide

Esters of phthalic acid are used as plasticizers in plastics, including food packaging [1]. However, these substances can migrate from plastic to the environment, even into food [2]. Commission Regulation (EU) No 10/2011 sets out specific migration limit for dibutyl phthalate 0.3 mg/kg and for di-(2-ethylhexyl) phthalate 1.5 mg / kg [3]. In particular, di-(2-ethylhexyl) phthalate (DEHP) is carcinogenic, teratogenic and affects the reproductive capacity of organisms [1].

This research builds on previous research, where various temperatures of meat heating were tested using sous vide technology. When the decreasing concentrations of phthalic acid esters with heat treatment were detected by sous-vide technology, both in the meat products and in the packaging [4]. In the subsequent research, the phthalate esters concentrations in used water, which was as a water bath, were also investigated [5].

In this our work, the effect of warming on the concentration of two phthalic acid esters: dibutylphtalate (DBP), di-(2-ethylhexyl) phthalate (DEHP)

in meat products prepared by sous-vide technology was investigated. When vacuum-packed meat was heat-treated at 60 ° C / 12 hr and frozen after the cooling until sampling time. One part was sampled immediately after thawing at 5 ° C, the other part after heating in a 60 ° C / 1 hour water bath. The samples were analyzed on the one hand in six replicates, three samples of plastics, and samples of used water from water bath (60 ° C / 1 hour). It was analyzed on HPLC.

Water without heating contained on average 1.22 μg/100 ml DBP and 0.29 μg/100 ml DEHP. After heating, it contained 1.22 μg /100 ml DBP and 0.20 μ/100 ml DEHP. Packages without further heating of 9.44 μg/g of DBP, 173.88 μg/g of DEHP, after heating 16.46 μg/g of DBP and 154.69 μg/g of DEHP. The meat samples again showed a higher average concentration of the two phthalates in the plastic wrapper with thermal warming. Without heat treatment, DBP 0.33 ug/g of original DEHP 6.61 ug/g of original mass. Thermal treatment of DBP 0.62 ug/g of original DEHP mass 18.79 ug/g of original mass.

References [1] Chemie potravin II. J. Velíšek, J. Hajšlová, Tábor, OSSIS, 2009. [2] B. Piotrowska, in Toxins in Food, W. M. Dąbrowski, Z. E. Sikorski, Boca Raton, CRC PRESS, 2005, p. 401. [3] Commission Regulation (EU) No 10/2011 of 14 January 2011 on plastic materials and articles intended to come

into contact with food. In: Official Journal of the European Union, L 12: 1–89. [4] M. Jandlová, A. Jarošová, J. Kameník, Hygiena a technologie potravin XLVII. Lenfeldovy a Höklovy dny: Sborník

přednášek a posterů, Brno, Czechia, 2017, p. 156. [5] M. Jandlová, A. Jarošová, J. Kameník, Sborník XLIV. konference o jakosti potravin a potravinových surovin, Brno,

Czechia, 2018, p. 139.

Acknowledgement The research was financially supported by the grant IGA FA MENDELU No. IP_2018/059.

68

Pigmented yeasts as biotechnological factories for bioproducts and

biofuels

Márová I.1, Szotkowski M.1, Vanek M.1, Byrtusova D.1, Rapta M.1, Haronikova A.1, Certik M.2,

Shapaval V 3

1 Materials Research Centre, Faculty of Chemistry, Brno University of Technology, 612 00 Brno 2 Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, Slovak

Republic 3 Norwegian University of Life Sciences, As, Norway

In nature, there exist a wide variety of microbes that can be of any economical importance to humans. A specialized group of microorganisms includes pigmented yeasts. They are yeasts that develop colored pigments as their secondary metabolites. Pigmented basidiomycetous yeasts like Rhodotorula and Rhodosporidium produce carotenoid pigments with antioxidant and provitamin A effects. Another pigmented yeast, Metchnikowia pulcherrima, produces extracellular red pigment which exhibits antimicrobial effect. Expect specific pigments, these yeasts can produce high amounts of proteins, intracellular lipids with high portion of PUFA, sterols (provitamin D), ubiquinone and beta-glucans. All these compounds

could exhibit important biological effect. Most of these metabolites are overproduced at specific cultivation conditions (e.g. C:N ratio, presence of stress factors, metal ions).

In this study, metabolomic analysis of yeast cells in various growth stages will be performed and control of simultaneous production of pigments, lipids, sterols, ubiquinone and beta-glucans will be discussed. Metabolic flux of nutrients and preccursors will be followed using advanced instrumental techniques (FTIR, FCS, LC/MS, MALDI/TOF). Whole biomass and some metabolites of pigmented yeasts can be used in food and feed supplements.

Acknowledgements This contribution was supported by projects LO1211/ERDF (MSMT CZ) and Lipofungi (Nr.268305 of the Research

Council of Norway).

69

Analytical and chemometric tools used for fruit juices authenticity

evaluation

Martin Polovka1, Blanka Tobolková1, Elena Belajová1, Mária Kopuncová1,, Ján Durec2

1 National Agricultural and Food Centre, VUP Food Research Institute, Department of Chemistry

and Food Analysis, Priemyselná 4, SK-824 75 Bratislava, Slovak Republic, [email protected] 2 McCarter, Bajkalská 25, 821 01 Bratislava, Slovakia; production premises: Budovateľská 1247/7,

SK-92901 Dunajská Streda, Slovak Republic

Keywords: fruit juices, authenticity, quality, spectroscopy, chromatography, chemometrics

Fruit juices belong to the most popular drinks all over the world. Their compositions as well as composition of concentrates of fruit juices, dehydrated fruit juices and fruit nectars, their reserved name/s, way of production and labeling of their properties are subjected to specific legislation [1]. Products fulfilling the criteria set by the legislation are considered authentic, while those different are non-authentic, false or adulterated. Adulteration practices may also affect the quality of the feedstock and thus of the whole production process and the final product. [2]

Quality of fruit juices produced without any additives is determined beside the other factors, by the quality of feedstock, which is affected also by many factors including ripening state of fruit, its production, harvesting and conditions.

With an aim to protect both, the producers of fruit juices as well as the consumers against illegal practices, there is an active movement towards collecting the characteristic markers of original foods and drinks including juices ant thus, set the standards typical for an authentic products. For this purposes, analysis of well defined juices including the feedstock of known origin and composition is necessary. Involvement of combination of highly sensitive analytical methods/assays is a logic consequence, as well.

In this contribution the correlations between the orange and pineapple fruit juice feed stocks origin, and their physicochemical properties are presented. Samples of well defined origin from Costa Rica, Ecuador, South Africa, Columbia, Ghana and Mauritius (pineapple) and from Greece, Mexico and Brazil (orange) were subjected to analysis involving spectroscopic (EPR and UV-VIS) and chromatographic (GC-GC/MS-GC-olfactometry, LC) techniques. Concentration of polyphenols, selected

antioxidants and antioxidant properties, color parameters, profile of selected organic acids, amino acids and metals, but also sugars and hydroxymethylfurfural were evaluated. To obtain complex information, basic characteristics comprising pH, °Brix, relative density, titratable acidity and formol number were also monitored.

The obtained experimental characteristics were processed by statistical analysis involving ANOVA Tukey HSD test and multivariate statistics in order to evaluate the correlations between the feedstock origin and their properties. Moreover, the effects of storage at defined conditions (7± 1°C, darkness, 20 weeks) of final pineapple juice, produced under the conditions of modified atmosphere on kinetics of changes of the monitored characteristics was studied, as well.

Results obtained clearly proved the hypothesis on the significant influence of the juice feedstock origin on the properties of the raw material and subsequently, quality of the produced fruit juice. The created databases of markers of orange and pineapple feedstock characteristics allowed unambiguous differentiation of samples according to the country of origin even when seasoning effects were included. The dynamics of changes in selected fruit juice characteristics of pineapple juices during the storage for 20 weeks after the production confirmed strong protective effect of modified atmosphere production on juice stability and quality.

Additional experiments are in progress to include into the forming databases the markers of additional authentic orange and pineapple juices as well as of those non-authentic, commercial. The variability based on seasoning effects is being included, as well

References [1] Directive 2012/12/EU of the European Parliament and of the Council. [2] F.A.I.M. - Food Authenticity - Issues and Methodologies. Michele Lees (ed.): Eurofins Scientific (1998).

ISBN 2-9512051-0-4.

Acknowledgement This contribution is the result of the project APVV-15-0023 „Quality and authenticity of fruit juices – study of

relationships between the origin of feedstock, processing technology and quality of fruit juices” and of the project ITMS 26220220175 „Improvement of nutritional and sensorial parameters of fruity and vegetable drinks via an inert gases application” implementation, supported by the Research & Development Operational Programme funded by the ERDF.

70

Influence of the postfermentation technologies on selected

chemical components of czech lager beer

Jaromír Pořízka1, Dominika Vopelková1, Václav Štursa1, Milena Vespalcová1, Pavel Diviš1

1 Brno University of Technology, Faculty of Chemistry, Institute of Food science and Biotechnology

Keywords: Beer, pasteurization, filtration, ICP-OES, HPLC

Beer is one of the most popular alcoholic beverages worldwide. Esspecially in the Czech republic, beer is the most consumed alcoholic beverage and it is also considered as a national symbol [1]. Beer technology is essentially based on age-proven practices which are not significantly changing over time. In the present times, improvements of the beer technology is mostly focused on the increase of the stability and shell life of beer. It is mainly achieved by the developement of post – fermentation technologies (mainly Filtration and Pasteurization). These treatments of the beer can significantly prolong durability, but it can also change the chemical composition of the beer which is closely connected with technological, sensoric and nutritional properties [2,3].

The aim of this work was to study the influence of the pasteurization and filtration on selected chemical compounds in beer. Specifically, the influence on elemental composition (P, Ca, K, Mg, Na, Cu, Fe, Mn, Si, Zn, Cr), content of organic acids, carbohydrates and phenolic substances. Effects of the post fermentation procedures were studied on 3 groups of Czech lager beers, treated by different postfermentation technologies (filtered unpasteurized, filtered pasteurized, and nonfiltered unpasteurized).

Samples of beer were collected directly from small breweries and also from standard and specialized markets. Only lager beers with 12 % of original extract were selected for the study.

Optical emission spectrometry with inductively coupled plasma (ICP-OES Horiba Jobin Yvone Ultima 2), Ion chromatography with conductivity detection (Metrohm 850 Professional IC) and HPLC with DAD and ELSD detection (Agilent 1260 infinity) were used for the analysis of beer.

Analysis of variance (ANOVA) was used to assess the impact of individual post-fermentation processes on the chemical composition of beer. ANOVA was set to 95% confidence interval.

Verifiable influence of postfermentation procedures was observed on the parameters Fe, Si, K, Mg, gallic acid, ferulic acid, catechin, fructose and glucose.

Higher average concentration of Fe and Si was observed in beer treated by filtration. Beer filters are composed from diatomaceous earth, which can release Si and Fe from its structure in acidic conditions. Average concentration of K and Mg was significantly higher in nonfiltered beer. It is probably caused by the release of biogenic elements from lysed yeast cells.

Significant degradation of Gallic acid and Catechin (P <0.0001) was detected in beers treated by combined postfermentation methods of filtration and pasteurization. This effect was probably caused by the increased temperature and oxidation during filtration and pasteurization. Similar result, but not as significant (P=0.012), was observed on content of Ferulic acid, which is more thermal resistant. These compounds are natural antioxidants important for the oxidation stability of the beer.

Filtration of beer had also important influence on level of residual monosacharides. From the data it was obvious, that concentration of Fructose and Glucose in nonfiltered samples were under the LOD. This finding is due to the fact that monosacharides in beer acts as main substrate for the secondary fermentation of yeasts after the bottling. Filtration and pasterization removes or inactivates biomass from beer, which leads to the stabilization of sacharide content. Level of residual sacharides also directly depends on the storage time.

Results of this study proved, that pasteurization and filtration can affect chemical composition of beers. Differences were observed in 9 of the 23 tested parameters. Those parameters plays important role in technological, nutritional and sensoric properties of beer like shell life, fermentation rate, stability of beer foam or antioxidation stability.

References [1] L. Chládek. Pivovarnictví, Praha, Grada, 2007. [2] G. Basařová. Pivovarství: teorie a praxe výroby piva. Praha, VŠCHT, 2010. [3] P. Kadlec, K. Melzoch, M. Voldřich. Procesy a zařízení v potravinářství a biotechnologiích. Ostrava, Key Publishing, 2013.

Acknowledgement This work was financially supported by the project: Materials Research Centre at FCH BUT Sustainability and

Development, REG LO1211, with financial support from the National Programme for Sustainability I (Ministry of Education, Youth and Sports) and FCH-S-17-4695.

71

Processing of pomace from chokeberry and elderberry

Milena Vespalcová1, Tereza Lošková2, Zuzana Jurečková2, Václav Štursa2, Jaromír Pořízka2, Pavel

Diviš2

1 Brno University of Technology, Faculty of Chemistry, Institute of Food Science and Biotechnology,

Purkyňova 464/118, 612 00 Brno, Czech Republic, [email protected] 2 Brno University of Technology, Faculty of Chemistry, Institute of Food Science and Biotechnology

Keywords: chokeberry, elderberry, pomace, anthocyanins, phenolics, food colorant

Chokeberry (Aronia melanocarpa, L.) and elderberry (Sambucus nigra, L) are fruit with exceptionally high levels of phenolic compounds. It is mainly of flavonoids, phenolic acids and anthocyanins. All of these substances are important for human health. They act against inflammations, suppresses fever, relieve pain, are able to eliminate free radicals from the cell [1,2].

Figure 1: chokeberry elderberry

Moreover, anthocyanins are very good colorants for slightly acidic foodstuff. They can very well replace synthetic food colors.

Phenolic compounds including anthocyanins are accumulated mainly in the peel. Hence, the majority of it remains in the leftovers after juice production. But in the Czech Republic all chokeberry and elderberry pomace are only composted as yet!

The aim of this study was to prepare extracts from chokeberry and elderberry pomaces and to determine their selected chemical parameters, which are important for the use in food industry.

Pomaces from chokeberry and elderberry were obtained by pressing the fruits with industrial hydraulic press. The extraction procedures have been optimized and obtained extracts were concentrated by vacuum evaporation. Concentrates and extracts were evaluated for total anthocyanins, total phenolics, as well as the scavenging activity against DPPH radical.

Polyphenols content was measured by using Folin-Ciocaltau agent for all samples. Diluted concentrates were measured spectrophotometrically at 750 nm. The resulting concentration of total phenolic substances was expressed as equivalent of gallic acid in mg of phenolic substances per 100 g of dried pomace.

Content of anthocyanins was measured by pH-differential method. Diluted concentrates were analysed by spectrophotometer at 510 and 710 nm. The final concentration of anthocyanin pigments was converted to cyanidin 3-glucoside.

Among the methods used to estimate the antioxidative properties in vitro, the most popular are those based on the scavenging of free radicals. We used EPR spectrometry with DPPH free radical [3]. The best results for extract of chokeberry pomace were acquired: total phenolics 7285,7 mg per L, total anthocyanins 277,4 mg per L. The yield of phenolic compounds in extract of elderberry pomace was 27,1 g per L and total anthocyanins 34,9 g per L.

References [1] C. Mitchell, R. M. Brennan, J. V. Cross, S. N. Johnson. Agric. For. Entomol. 13, (2011) 3. [2] M. F. Ramadan. Food Res. Int. 44, (2011) 7. [3] G. C. Yen, H.Y. Chen. J. Agric. Food Chem., 43 (1995), 27.

72

Influence of aroma compounds on sensory quality of processed

cheese analogues

Eva Vítová, Michal Sýkora, Martina Mahdalová, Kateřina Sůkalová

Faculty of Chemistry, Brno University of Technology, Department of Food Chemistry and

Biotechnology, Purkyňova 118, 612 00, Brno, Czech Republic; [email protected]

Keywords: cheese analogues, flavour, SPME, GC, sensory analysis

Cheese analogues are products similar to cheese, in which milk fat, protein or both are partially or wholly replaced by non-milk-based components, mostly of vegetable origin. They are also labeled as imitation, substitute, artificial etc. They were developed in the United States in the early 1970s with the main aim to create cheaper product for the convenience food sector. They can have numerous applications as an ingredient in

salads, sandwiches, cheese sauces, cheese dips etc. 1. There is a little specific legislation covering cheese

analogues, however, the labeling should clearly distinguish them from cheese; they are not allowed to be named as “cheese” (Directive 397/2016 Coll. (2016)).

Low cost and storage stability are the main advantages of these products, moreover, they can offer many special dietary benefits as e.g. low in calories, saturated fat, sodium, cholesterol, lactose or

phenylalanine-free, vitamin enriched etc. 1. On the other hand, changes in composition can alter the sensory properties, especially texture and flavour. Flavour is the most important negative attribute of analogues, described as “bland”, not comparable to the real cheese. For this reason, many flavouring systems are used in industry, mainly in the form of extracts of aroma

compounds of natural and/or synthetic origin 2,3. Although these products are now common in the

market, there is a little published information about their sensory quality. There are only several works dealing with

the flavour of analogues 26, most of them compare flavour of analogues with corresponding processed cheese; how exactly the substitutions of raw material influence flavour is not fully understood.

The aim of this study was to identify and quantify aroma compounds in samples of cheese analogues and judge their influence on sensory quality/flavour. Model samples (40% dry matter, 50% fat in dry matter) were produced at laboratory (pilot plant) conditions using standard producing technology with addition of different vegetable fats (coconut fat, palm oil, sunflower oil). Classical processed cheese with butter was used as standard.

Aroma compounds were isolated by solid-phase microextraction and assessed by gas chromatography with flame ionization detection. The sensory characteristics (appearance, color, gloss, odour, taste/flavour and texture) were evaluated using seven-point hedonic scale (1 unacceptable ⇒ 7 excellent) (ISO 4121:2003); selected taste descriptors (sour, salty, bitter, cheesy, oily) were evaluated using profile test (1 imperceptible ⇒ 7 very strong) (ISO 13299:2016). Students of FCH BUT in Brno were selected and trained for sensory evaluations.

In total, 31 volatile aroma compounds were identified and quantified in samples, 6 aldehydes, 7 ketones, 12 alcohols, 3 esters and 3 fatty acids. Alcohols and acids were quantitatively the most important. Significant differences (P < 0.05) in content of aroma compounds were found among samples of cheese analogues.

Based on sensory evaluation, 24 compounds were found as possible contributors to flavour of samples. Analogue with coconut fat contained the highest content of compounds identified; simultaneously, it was also evaluated as the most tasty/most acceptable.

References [1] H.P. Bachmann, International Dairy Journal 11 (2001) 505. [2] S.L. Drake, M.D. Yates, M.A. Drake, Journal of Sensory Studies 25 (2010) 720. [3] C.R. Cunha, A.I. Dias, W.H. Viotto, Food Research International 43 (2010) 723. [4] D.D. Muir, A.Y. Tamime, M.E. Shenana, A.H. Dawood, LWT-Food Science and Technology 32 (1999) 41. [5] N. Noronha, D.A. Cronin, E.D. O'Riordan, M. O'Sullivan, Food Chemistry 106 (2008) 905. [6] M. Yalman, O. Guneser, Y. Karagul, Tarim Bilimleri Dergisi-Journal of Agricultural Sciences 1 (2017) 63.

Acknowledgement This work was supported by a Standard project of specific research No. FCH-S-18-5334.


73

Is rapeseed oil suitable for frying French fries?

Lucia Zeleňáková 1, Mária Angelovičová1, Marek Šnirc2, Jana Žiarovská3, Stanislav Kráčmar4, Branislav

Gálik5

1 Department of Food Hygiene and Safety, Faculty of Biotechnology and Food Sciences, Slovak

University of Agriculture, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic, [email protected] 2 Department of Chemistry, Faculty of Biotechnology and Food Sciences, Slovak University of

Agriculture, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic 3 Department of Genetics and Plant breeding, Faculty of Agrobiology and Food Resources, Slovak

University of Agriculture Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic 4 College of Business and Hotel Management (CBHM), Bosonožská 9, 625 00 Brno, Czech republic 5 Department of Animal Nutrition, Faculty of Agrobiology and Food Resources, Slovak University of

Agriculture, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic

Keywords: rapeseed oil, deep-frying, TPC, peroxide and acid value, fatty acid composition

Our results, supported by other studies, provided the basis for choosing the suitable vegetable oil as well as rapid-measuring device to control the quality of frying oil in restaurants. The goal of our study was to analyse thermo-degradative changes of rapeseed oil during deep-frying French fries. In this context the purpose of our experiment was to examine the effect of deep-frying process on fatty acids composition, acid value, peroxide value and content of TPCs in rapeseed oil.

Deep frying is classified as hot-fat cooking method (170°C – 200°C). Typically, deep frying cooks food quickly: all sides of a food are cooked simultaneously as oil has a high rate of heat conduction Deep frying is commonly utilized for food preparations such as frozen pre-fried foods, snack foods and fast foods [1, 2].

Slovak legislation [3] requires that deep-fat frying be carried out in accordance with good manufacturing practice and frying fats should not be heated above 180 °C (not longer than 24 hours of continuous frying). However, practice shows that, especially, operators of fast food restaurants often violate these requirements and use "frying" oils for several days. TPCs values measured by Testo 270 grown in rapeseed oil continuously since the first deep-frying. TPCs content in the fresh oil was 3.3% and the threshold (24%) was achieved on the fourth day. The total time for the deterioration of deep-frying rapeseed oil was 23

½ hours.

The statistical analysis (Scheffe´s test) showed that TPCs content was similar or lower at 8 o´clock compared to previous day (at 14 o´clock). However, this finding was not statistically significant (>0.05). At the beginning of

deep-frying French fries in rapeseed oil, the acid number was 0.374 mg KOH/g and 1.271 mg KOH/g

at the fourth

day of depp-frying. The measured peroxide value was 4.3 mEq O2/kg at the beginning and at the end of deep-frying 10.5 mEq O2/kg. It should be note that both parameters were below the limit of refined oil according to Slovak legislation [4]. However, detected values varied during deep-frying process.

Table 1: Parameters of linear regression for TPCs, peroxide value and acid value in rapessed oil during deep-frying French fries

Summary

output TPCs (%)

Peroxide value

(mEq O2/kg)

Acid value (mg

KOH/g)

Model y = 3.04 +

0.7942x y = 3.48 + 0.2481x

y = 0.31 +

0.038x

Multiple R (r) 0.997 0.933 0.886

R Square (R2) 0.994 0.871 0.785

P- value 5.24.10-57

4.49.10-13

3.71.10-10

Intercept 3.04 3.48 3.11

Slope 0.794 0.25 0.038

MUFA were predominatly observed in fresh rapeseed

oil (61.22%). The initial content of saturated fatty acids (SFA) in rapeseed oil was 6.94%, over the deep-frying process increased to 7.14, 7.33, 7.59 and 8.03%. The important groups of fatty acids in fresh rapesed oil were PUFA which have in principle a significant effect on oil deterioration. The content of PUFA in oil was reduced by about 9.42% while the initial content was 28.14%.

References [1] Gertz, C., European Journal of Lipid Science and Technology 116 (2014) 669-674.

[2] Zeleňáková, L., Pastyriková, S., Židek, R., Mura, L., Potravinárstvo 6 (2012) 45-51. [3] Decree of the Ministry of Health of the Slovak Republic no. 125/2017 which amends Decree no. 533/2007

[4] Decree of the Ministry of Agriculture and Rural Development of the Slovac Republik no. 424/2012

Acknowledgement This study was supported by the Project KEGA No. 007SPU-4/2017


74

Physical Chemistry & Life

with Special Session on Advanced Fluorescence

Techniques

75

Influence of surfactant concentration on hyaluronan hydrogel

microstructure characteristics measured by FRET

Zuzana Adamcová1, Filip Mravec1, Miloslav Pekař1

1 Brno University of Technology, Faculty of Chemistry, Institute of Physical and Applied Chemistry

Purkyňova 464/118, 612 00 Brno; [email protected]

Keywords: hyaluronan, hydrogel, Septonex, energy transfer, perylene, fluorescein

This contribution is focused on utilization of fluo-rescence techniques in description of hyaluronan-surfactant hydrogel microstructure.

Investigated hydrogels were prepared by mixing 2% sodium hyaluronan (HA) solution with Septonex solution, both containing 0.15 M NaCl. Influence of surfactant concentration in used stock solution (50, 100 or 200 mM) on hydrogel characteristics was studied utilizing Förster Resonance Energy Transfer (FRET). Perylene-Fluorescein in low concentration was used as donor-acceptor pair for which binding and effectivity of energy transfer in both supernatant and gel phase were evaluated. Both fluorescence probes were solubilized in the Septonex stock solution prior to mixing with HA stock solution. The aim of these experiments was to describe eventual changes in hydrogel microstructure dependent on quan-tity of Septonex micelles available for interactions with HA.

As Perylene is expected to be solubilized in the hydrophobic core of Septonex micelles and Fluorescein dissolved in the outer solution (and thanks to its negative charge electrostatically attracted to the positive charge of Septonex head part), the FRET effectivity is likely to change with changing size or shape of the micelles. In case, that such a change is caused by interaction with hyaluronan and creation of gel phase, this parameter should be sensitive enough to describe it and provide valuable insight into hyaluronan hydrogel microstructure. FRET parameters in supernatant were also studied in order to compare them with hydrogel characteristics.

Binding parameter (which describes fraction of donor interacting with acceptor in means of energy transfer) was evaluated for supernatants, as well as hydrogels.

It was found to remain constant (average value 4.1 ± 0.4 %) in all measurements. This is partly due to concentration of both perylene and fluorescein, which was kept the same for all measurements, but it also shows, that both hydrophobic and hydrophilic substances are equally incorporated into hydrogel.

Experimental values of FRET effectivity (which is in particular system function of distance between donor and acceptor) are summarized in Table 1. Higher values of energy transfer effectivity in supernatant comparing to hydrogel phase were not expected because of

macroscopically more rigid gels created when using 200 mM Septonex. Possible explanation for such finding is that fluorescein molecules might be displaced by hyaluronan chains interacting with Septonex micelles, which would enlarge distance between Fluorescein and Perylene located in the hydrophobic micellar core. With increasing Septonex concentration there are more micelles available for interaction with hyaluronan, which results in decrease of average FRET effectivity.

Table 1: Differences in FRET effectivity in supernatant and gel phase for different hydrogels

Gel prepared with 50 mM

Septonex


Septonex


Septonex

Supernatant eff. [%]

57.0 ± 4.1 62.0 ± 6.1 60.0 ± 3.6

Gel eff [%]

56.0 ± 2.9 55.0 ± 2.6 51.0 ± 3.4

Difference [%]

1.8 11.3 15.0

It is obvious, that differences in effectivity of FRET between supernatant and gel phase tend to increase with increasing concentration of Septonex stock solution. Whereas in the first two cases (50 and 100 mM Septonex) the effectivity values for supernatant and gel are within experimental error, measurements in the hydrogel with 200 mM clearly show decrease of FRET effectivity in hydrogel with respect to supernatant values. This trend is in agreement with proposed explanation involving increasing number of micelles interacting with hyaluronan chains in contrast to unbound micelles (similar to these in supernatant) with Fluorescein located in the close proximity to Septonex charged haeds.

In conclusion it is possible to say that differences between supernatant and hydrogel microstructure were measured using FRET effectivity. These differences were more pronounced with increasing concentration of Septonex micelles in the system, which might indicate stronger interactions between polyelectrolyte and surfactant. More experiments will be needed in order to understand hydrogel microstructure in detail.

Acknowledgement This work was supported by Materials Research Centre at FCH BUT- Sustainability and Development, REG LO1211, with

financial support from National Programme for Sustainability I (Ministry of Education, Youth and Sports).

76

Förster Resonance Energy Transfer between Perylene and

Fluorescein in Cationic Micellar Solutions

Petra Holínková1, Filip Mravec1, Miloslav Pekař1

1 Brno University of Technology, Faculty of Chemistry, Materials Research Centre, Purkyňova 118,

612 00 Brno, Czech Republic, [email protected]

Keywords: FRET, fluorescence quenching, CTAB, Septonex

Fluorescence energy transfer via Förster mechanism occurs by a radiationless, coulombic, dipole-dipole interaction between two molecules (donor and acceptor) and is active over a range from 1 to 10 nm. This interaction requires spectral overlap between the donor emission and acceptor’s absorption, along with the suitable orientation of their transition dipoles. This process is dependent upon the donor-acceptor distance. Therefore, energy transfer has been proposed as a spectroscopic measure for determination of inter-chromophore distances in macromolecules and micro-heteregenous systems. This makes it a well suited technique to probe nanoscale processes.

Figure 1: Fluorescence spectrum of perylene (red line) and absorption spectrum of fluorescein (blue line) in 2 mM Septonex solution.

This contribution deals with an experimental study on the FRET process between perylene as a donor and fluorescein as an acceptor in two different cationic surfactant solutions (CTAB, Septonex) above its critical

micelle concentration. Studied of energy transfer in micelles are especially interesting because these systems provide a structure where it is possible to get high local concentration and spatial proximity between donor and acceptor molecules. Perylene is located in hydrophobic core of micelles, while fluorescein is micellized in the inner part of the Stern region.

Figure 2: Localization of perylene (D) and fluorescein (A) in the cationic micelle.

The Förster distance, which is the distance at which energy transfer is 50% efficient and which is characteristic for the donor-acceptor pair, was determined. The micellar radius for both surfactants was calculated from obtained data. Also the influence of the fluorescein concentration and time dependency on the energy transfer efficiency we studied by steady-state and time-resolved fluorescence measurement.

References [1] F.G. SÁNCHEZ, C.C. Ruiz, Journal of Luminescence, 69 (1996), 179.

Acknowledgement This work was supported by Materials Research Centre at FCH BUT- Sustainability and Development, REG LO1211, with

financial support from National Programme for Sustainability I (Ministry of Education, Youth and Sports).

77

Preparation and research of cosmetic emulsions from solid TiO2 and

emulsions prepared from dispersion of TiO2

Sabina Jarabkova1, Marcela Lastuvkova2, Adam Jugl3, Tomas Velcer4, Jiri Smilek5

1 Brno University of Technology, Faculty of Chemistry, Purkyňova 464/118, 621 00 Brno, Czech


Keywords: cosmetic emulsion, TiO2, sun protection factor, SPF determination, sunscreens, UV filters,

stability tests

The main aim of this work is preparation and characterization of cosmetic emulsions with different addition of TiO2 and different sun protection factor (SPF). TiO2 is the main component (main UV filter) of all emulsions in this study. TiO2 was used in dispersed form and in the form of a powder. A wide range of O/V emulsions were prepared. The preparation of the emulsion product allows the formation and combining of otherwise incompatible ingredients in an effective and commercially desirable cosmetic product. A key point in product development is the choice of suitable raw materials and the emulsion preparation method because materials and preparation method affect properties of the resulting emulsion such as stability, viscosity and others. The stability of the emulsion depends on various parameters such as particle size, crystal formation, activity of the components used to achieve the desired rheological properties of the product. These parameters depend on temperature so the rate of heating, the method and the rate of mixing of the phases and the cooling rate are very important. An analytical centrifuge was used to determine the stability of the emulsions and the results obtained by analytical separation were

compared with gravity stability tests. Mechanical properties of prepared emulsions were tested by rotational rheometer.

Nowadays there is an extensive list of active ingredients that can be used as additives for various cosmetic emulsions. The choice is limited by the laws of the state in which the final product is to be placed on market. In this study the combinations of UV filters (which are allowed in Czech Republic of course) were used to obtain final products with different values of SPF.

The SPF values in this study were determined by an in vitro tests. This method evaluates the UV transmission through a thin layer of the sunscreen product. The whole experiment was performed on the defined roughness plates on which the product was torn. These plates must be UV transparent, inert to all components contained in the product, photostable, and must not be fluorescent when irradiated. A spectrophotometer with an integration ball was used to determine SPF. To determine the accuracy of our measurements, we compared them with the spectrophotometric SPF values of the commercial products.

Acknowledgement The work has been supported by the project LO1211 from National Programme for Sustainability I (Ministry of

Education, Youth and Sports).

78

Study of Electrostatic Interactions between Hyaluronan and Amino

Acids

Adam Jugl1, Miloslav Pekař2, Hejná Jana

1 Materials Research Centre, Faculty of Chemistry, Brno University of Technology, Brno, Purkyňova

464/118, Brno 61200, Czech Republic, [email protected] 2 Materials Research Centre, Faculty of Chemistry, Brno University of Technology, Brno, Purkyňova

464/118, Brno 61200, Czech Republic

Keywords: hyaluronan, amino acid, polyarginine, ITC, HRUS

This paper focuses mainly on the use of isothermal titration calorimetry (ITC) and high-resolution ultrasonic spectroscopy (HRUS) in the study of interactions between the negatively charged polysaccharide hyaluronan and positively charged amino acids. Due to the opposite charge of the two polymers, the nanoparticles formed by the electrostatic forces between the polymers occur when they are mixed [1].

Interaction between hyaluronan (9 kDa and 1.39 MDa) and amino acids of different variants (arginine and lysine) were studied. Amino acid solutions were titrated to hyaluronan solutions of various molecular weights. At first, interactions between hyaluronan and simple amino acids, including the hydrochloride form, were studied. For simple amino acids, all the interactions had the same endothermic course. It appears from the results that, rather than the formation of larger particles, the original hyaluronan structures present in the solution at the beginning of the experiment break down during the titration. Subsequently, interactions with arginine oligomers (dimers, tetramers and octamers of arginine) in monohydrochloride form were studied. The concentrations were set such that the amount of charges, which carry the amino acids was nearly five times higher

in the end of the titration than the number of charges in a solution of hyaluronate.

If the length of the poly amino acid chain length is sufficiently prolonged, hyaluronan begins to aggregate with the amino acid forming nanoparticles. The second part of this work is focused on the preparation and characterization of nanoparticles formed by electrostatic interactions using negatively charged polymer hyaluronan and polyarginine of molecular weight ranging from 5 to 15 kDa in hydrochloride form.

Unlike the previous study [2], where the effect of PBS on nanoparticles was studied, was decided to study nanoparticles in terms of stability by addition of sodium chloride and by lyophilization and re-dissolving. NaCl was added to the prepared solution of nanoparticles to a concentration of 0.15 M to simulate physiological environment. The results show that the particles in both cases increased their size.

Due to the composition of nanoparticles from biodegradable materials, particles may be attractive for medical applications. Particle size was studied using dynamic light scattering.

References [1] KIM, Eun‐Joong, et al. Hyaluronic acid complexed to biodegradable poly L‐arginine for targeted delivery of siRNAs.

The journal of gene medicine, 2009, 11.9: 791-803. [2] OYARZUN-AMPUERO, Felipe A., Francisco M. GOYCOOLEA, Dolores TORRES a Maria J. ALONSO. A new drug

nanocarrier consisting of polyarginine and hyaluronic acid. European Journal of Pharmaceutics and Biopharmaceutics. 2011, 79(1), 54-57. DOI: 10.1016/j.ejpb.2011.04.008. ISSN 09396411.

Acknowledgement This work has been supported by the project LO1211 from National Programme for Sustainability I (Ministry of Education, Youth and Sports).

79

Study of flow properties of powders in pharmaceutical industry

Pavel Kolesa1

1 Material Research Centre, Faculty of Chemistry, Brno University of Technology, Purkyňova

464/118, 612 00 Brno, Czech Republic; [email protected]

Keywords: API, caking, flow properties, handling, process, Mycophenolic Acid

Since bulk solids handling, in general, is one of the crucial industrial activity it is very important to study flow properties of powders. The importance of flow properties in pharmaceutical industry has been recognized over many decades and plays a significant role in a handling and process abilities as well as it influences also final properties of drug product itself. Due to logistical reasons are powders of APIs (active pharmaceutical ingredients) and excipients often stored for a long time in different conditions [1].

The storage or transport can cause adverse impact on unwanted agglomeration generally referred to as “caking”. This is mainly caused by migration of the moisture within bulk powders. Due to high prices of API in pharmaceutical industry as well as since the final drug product quality may be affected by this phenomenon, it is required to study mechanism of caking.

The purpose of this work is study and find relevant parameters (or physicochemical properties) which the most affect tendency of the model API to caking. The immunosuppressant drug Mycophenolic Acid (MPA) was chosen such as model substance for this study.

Figure 1: Problematic production batch of Mycophenolic Acid containing hard lumps

Several production batches of MPA was analyzed by using different instrumental techniques in order to study polymorphism, morphology, flow properties, particle size distribution, hygroscopicity, surface area… Physicochemical properties and relevant parameters of problematic production lots containing visible lumps and causing several issues in production were compared with properties and parameters of convenient and non-problematic lots. Table 1 below shows studied parameters and relevant instrumental techniques.

Table 1: Studied properties and relevant techniques Studied properties Relevant techniques

Polymorphism X-Ray Powder Diffraction (XRPD) Morphology Scanning Electron Microscope

Flow properties Powder Rheometer FT4 Particle size distribution (PSD) PSD by Laser Diffraction Method

Hygroscopicity Dynamic Vapor Sorption Surface area Specific Surface Area Analyzer

One of the most important parameter describing flow

properties is BFE (Basic Flowability Energy) measured by FT4 Powder Rheometer. This value was measured in initial state and after exposure to stress conditions, such as relative humidity, mechanical pressure…

The results of this study can help in development of APIs to achieve physicochemical parameters using suitable crystallization technique, solvent or technological operation such as milling or micronization.

References [1] T. Freeman, K. Brockbank, B. Armstrong. Measurement and Quantification of Caking in Powders. Procedia

Engineering. 2015, 102, p. 35-44 [2] J. E. Bronlund, T. Paterson. Mathematical modelling of temperature induced moisture migration in bulk powders.

Chemical Engineering Science. 2008, 63(9), p. 2330-2340

80

Sorption of Water Humidity by Selected Biopolymers by Means of

Microcalorimetry

Jitka Krouská1, Tomáš Bola2, Vojtěch Enev1, Miloslav Pekař1,2

1 Materials Research Centre, Faculty of Chemistry, Brno University of Technology, Purkynova

464/118, 61200 Brno, Czech Republic, [email protected] 2 Institute of Physical and Applied Chemistry, Faculty of Chemistry, Brno University of Technology,

Purkynova 464/118, 61200 Brno, Czech Republic

Keywords: sorption, water humidity, biopolymer, microcalorimetry

This study is focused on a special kind of experiment which can be performed using a TAM III microcalorimeter. It is the water sorption experiment which occurs in 4 ml closed glass ampoules with an insert inside. The insert can basically contain any solvent. In our case, empty inserts, inserts with water and with two different saturated salt solution (NaCl and CaCl2), respectively, were used to obtain different water humidity environment inside the measuring ampoule above the sample. The schematic picture of such an ampoule with the sample (powder) is presented in Fig. 1.

Figure 1: Schematic picture of the measuring ampoule with a sample (left) and the real ampoules (right).

For this purpose, several biopolymers common in the

author’s laboratory were used. The experiments were performed with amorphous lactose, hyaluronan, dextran, chitosan and sodium alginate at two temperatures (25 and 35°C). Amorphous lactose, which was prepared from the crystalline powder by lyophilization, was chosen as a model sample which sorption ability is published in a lot of papers, e.g. by Ramos et al. [1]. Other samples vary in their origin, functional groups – structure or molecular weight therefore the results are discussed from this point of view.

The selected results of hyaluronan (HYA, molecular weight 250-450 kDa) and amorphous lactose (LACT) at 25°C are summarized in Fig.2.

Figure 2: Sorption behavior of hyaluronan and amorphous lactose with different insert filling at 25°C.

The data show the increasing (exothermic) peak between 0 and 5 hours which corresponds to sorption process occurring in the measuring cell.

As expected, the most intensive signal was observed with samples with water (100% relative humidity) and the less intensive signal corresponds to air (empty inserts) and CaCl2. It is supported by the fact that the saturated solution of CaCl2 gives the relative humidity of 35 % which is very close to relative humidity of air. Additionally, the sorption of water and lactose was slower compared to the other samples – the signal is back to zero heat flow after more than 10 hours of the experiment while the other reactions were completed in 7 hours.

The other samples gave analogous results and the higher temperature increased the signal intensity of the sorption. In addition, well-known hyaluronan hydration ability was proved due to the most intensive signal in water environment.

References [1] R. Ramos, S. Gaisford, G. Buckton, International Journal of Pharmaceutics, 300 (2005) 13-21.

Acknowledgement This work has been supported by project “Materials Research Centre at FCH BUT – Sustainability and Development” No.

LO1211 of the Ministry of Education, Youth and Sports of the Czech Republic.

81

Complex characterization of agarose hydrogels

Marcela Lastuvkova1, Milan Kracalik2, Jiri Smilek1

1 Brno University of Technology, Faculty of Chemistry, Materials Research Centre, Purkynova

464/118, 612 00 Brno, Czech Republic, [email protected] 2 Johannes Kepler University Linz, Institute of Polymer Science, Altenberger Straße 69, 4040 Linz,

Austria

Keywords: agarose, hydrogel, rheology, viscoelastic properties.

Agarose hydrogels belong to one of the most popular materials used in pharmaceutical area or in biomedicine. This thermorevresible polysaccharide can be used like a tracer of active compounds or development of new materials for cosmetic or food industry, biotechnology or for laboratory experiments as a carrier material (matrix) for diffusion, electrophoresis, study of barrier properties and reactivity compound, etc. It is obvious that agarose hydrogels are widespread utilized materials in different scientific branches or common life.

Our experiments are based on the penetration of active compounds through plant cuticles, which are isolated from leaves Prunus laurocerasus and the model uses for determination of simulation foliar fertilization the agarose hydrogels. The model is called diffusion pair, which is consisted of 1 wt. % agarose hydrogels, which are prepared into the clear cuvettes. These cuvettes are called receiving hydrogels, because they accept the studied compounds penetrated through leave surface (cuticles). Other hydrogels formed by 1 wt. % agarose with addition of 1 wt. % of potassium lignohumate (LH) (AMAGRO s.r.o) is called resourcing hydrogel, because it is reservoir of diffusing compound. Between these two hydrogels plant cuticle isolated from leave has been fixed (Figure 1).

Figure 1: Diffusion pair for like a model for simulation of foliar fertilization.

The diffusion experiments usually took 14 days and during this time the hydrogels could change the properties, especially from viscoelastic properties point of view, because of syneresis of hydrogel or drying, which is possible although the diffusion pairs are stored in desiccator with water (almost 100 % humidity during the whole experiment). Therefore it is very important to know mechanical properties of hydrogels, because the rate of diffusion processes could be influenced by the change in mechanical properties during experiments.

Rheology is a scientific field of determination of viscoelastic properties of materials. Measurements are realized by rheometers, which are used to determine the deformation and flow behaviour of different kind of materials. Our measurements were realized by rheometer from Anton Paar (MCR 501 and 502) at Johannes Kepler University Linz. Agarose hydrogels with different concentration 1, 0.5, 0.1 wt. % have been studied by simple oscillation experiments and the same hydrogels with addition of AMAGRO products (1 wt. %) were compared. We would like to determine differences in mechanical properties between pure agarose hydrogels and hydrogels with LH. The pictures from scanning electron microscopy (ZEISS EVO LS 10) show differences in surfaces between clear hydrogels and others (Figure 2).

Figure 2: Surface of pure agarose hydrogel (left) and agarose hydrogel with addition of lignohumate (right).

Acknowledgement This research project has been supported by project AKTION 79p6 “Characterization of hydrogels systems by advanced

macro-rheological, micro-rheological and spectroscopic techniques - extension” and by project “Materials Research Centre at FCH BUT – Sustainability and Development” REG LO1211, with financial support from National Programme for Sustainability (Ministry of Education, Youth and Sports).

82

Fluorescence Techniques in Hydrogel Characterization

Filip Mravec

Institute of Physical and Applied Chemistry & Materials Research Center, Faculty of Chemistry,

Brno University of Technology, Purkyňova 464/118, 612 00 Brno, Czech Republic,

[email protected]

Keywords: fluorescence, hydrogel, fluorescence microscopy, hydrophobic domains

This work is focused on different fluorescence techniques which can be useful in research of phase-separated hydrogels. These hydrogels are formed from oppositely charged polymers and surfactant and can be promising materials in acute wound healing as well as local drug delivery systems.

Phase separated hydrogels are based on polymer and micelle-like nanocontainers form physically stabilized 3D network. In principal this system has aqueous as well as oil-like phase and it is able to solubilize hydrophilic as well as hydrophobic species.

Our hydrogel contains at least 93 % of water allows the hydrophilic species to diffuse in or out from the gel. Rate of diffusion of different species inside gel matrix seen by fluorescence correlation spectroscopy is discussed a results are correlate with species structures.

Figure 1: Phase separated hydrogels, based on hyaluronan and cetyltrimethylammonium bromide, with solubilized Nile red, Perylene, Anthracene, Rhodamin 6G, Doxurubicin, and Riboflavin (from left to right)

This research extends the knowledge about the detailed characterization of the inner environment of the hydrogel by determining the diffusion behavior of the fluorescent probes Atto 488 and Nile red using fluorescence correlation spectroscopy (FCS) technique and its modified version dual-focus fluorescence correlation spectroscopy (2f-FCS).

Compared results, in Table 1, showed that both methods show similar values and probes specifically interact with CTAB but Atto 488 shows only weak

interaction with Septonex® compared to Nile Red. Additionally, these interactions were not affected by the molecular weight of hyaluronan.

Table 1: Diffusion coefficients of Nile red and Atto 488 as function of molecular weight of hyaluronan in phase separated hydrogels prepared with different surfactants.

CTAB

360 kDa CTAB

1,56 MDa Septonex®

360 kDa Septonex® 1,56 MDa

µm2·s

-1 µm

2·s

-1 µm

2·s

-1 µm

2·s

-1

Nile red 5.19 ± 0.04 5.42 ± 0.04 10.01 ±

0.05 8.41 ± 0.02

Atto488 53.05 ± 0.50 51.2 ± 2.34 80.33 ±

6.71 85.82 ±

4.27

Fluorescence spectra of probes, which helps to

determine hydrophobic domain qualities, from hydrogel were measured with optical fibers sample compartment. Free endings of optical fibers were built-in through the top of polystyrene box with fixed angle between excitation and emission channel. Hydrogel sample was applied on glass slide and placed under the excitation beam. In real-time-monitoring option was found final position with the highest fluorescence count rate at fixed emission and excitation wavelengths. After this aligment a fluorescence spectrum was taken in a proper range.

Figure 2: Self-made sample chamber for measuring fluorescence spectra from hydrogel samples (Nile red condition).

Results from steady-state measurements confirms preservation of hydrophobic domains properties.

Acknowledgement This work was supported by Czech Science Foundation, project 16-12477S, and by the project Materials Research

Centre at FCH BUT- Sustainability and Development, REG LO1211, with financial support from National Program for Sustainability I (Ministry of Education, Youth and Sports).

83

Design of nanostructure models using grammatical evolution

Pavel Osmera senior1, Daniel Zuth1, Anna Kucerova1, Pavel Osmera junior2, Monika Dosoudilová1, Jan

Muller1, Tomas Marada1, Ladislav Dobrovsky1

1 Brno University of Technology, Department of Automation and Computer Science

Technicka 2, Brno, Czech Republic 2 Department of Nuclear Medicine, Masaryk Memorial Cancer Institute, Brno, Czech Republic,

[email protected]

Keywords: vortex-fractal-ring-structures, grammatical evolution, models of atoms and molecules,

atom structure of graphene

New VFRT (vortex-fractal-ring-theory) works with fractal annular structure of the electron, proton and neutron, and can describe the inner structure of atomic nuclei. The atomic nucleus can be built from the ring protons and neutrons using the following rules:

The proton cannot be directly connected with the proton, except for two parallel protons with the same axis that are connected together by nuclear forces.

Next proton with a different axis can be connected via the coupling neutron to another proton.

On one axis can be maximally two protons and two neutrons and two electrons with opposite spins.

It seems that the combination of these three basic rules can create any real structure of atoms. On figure red rings are protons, yellow rings are neutrons. The green arrows determine the input directions of the magnetic moments of carbon, yellow arrows are output direction of the magnetic moments. Black spheres are simplified carbon atoms.

VFRT (vortex-ring-fractal theory) is a new and original view of elementary particles and the structure of atomic nuclei, atoms and molecules. Its basics are simple for understanding through comprehensive topological structure that does not need to describe their complicated mathematical apparatus. This theory, based on the use of the vortex, fractal and ring structures, interconnects all the current knowledge. VFRT together with grammatical evolution can design new nanostructures. It allows us to understand the fundamental physical and chemical reasons for the stability and reactivity of atoms and molecules. Grammatical evolution is a suitable tool for optimizing the design of new nanostructures. This new way of designing nanostructures has been tested on the graphene structure.

Figure 1: Ring model of the carbon nucleus

References [1] Organov, A.R.: USPEX, Universal Structure Predictor, 2004, http://uspex-team.org/en/uspex/overview [2] Pauling, L.: General Chemistry, Dover publication, Inc, New York, 1988 [3] Ramsden, E.N.: A-Level Chemistry, Nelson Thornes Ltd, fourth edition, 2000 [4].Heyrovska, R.:The golden ratio, ionic and atom radii bond lenth, Molecular Physics,ISSN0026-8976, 2005 [5] Zmeskal, O., Nezadal, M., Buchnick, M.: Fractal-Cantorial geometry, Hausdorf dimension and fundamental laws of

physics, Chaos, Solit atom radii bond lenth ons and Fractals 17, 2003, 113-119 [3] Osmera, P.: The Vortex-ring-fractal Structure of Hydrogen Atom, Proceeding of WCECS 2009, 2009, San Francisco,USA,

89-94 [6] O`Neill, M., Ryan, C.: Grammatical Evolution: Evolutionary automatic programming in an arbitrary language. Kluwer

Academic publishers, 2003, 160 p. [7] Fenton, M., McDermott, J., Fagan, D., Forstenlechner, S., Hemberg, E., O’Neill, M. PonyGE2: Grammatical Evolution in

Python, In proceedings of GECCO 17 Companion, Berlin, 2017, 8 pages [8] Osmera, P., Popelka, O., Panacek, T.:Grammatical Evolution with backward processing. In proceedings of 12th Zittau

East-West Fuzzy Colloquium. Zittau, 2005, p.235-244 [9] Osmera, P.,Werner, P.: Ring structure of atoms and molecules, Proceedings of SPIE Vol.95701C-1, San Diego, 2015 [10] Werner, P.: Základy modelování prstencové struktury elementárních částic hmoty, Ústav teoretické a experimentální

elelektrotechniky, Brno, 2018, ISBN 978-80-214-5620-4, https://www.ringtheory.eu/ [11] More about VFRT can be found on http://www.pavelosmera.cz/public/public.html

mailto:[email protected]%20i


http://www.pavelosmera.cz/public/public.html

84

What keeps polyhydroxyalkanoates in bacterial cells amorphous?

A contribution from stress-response experiments

Petr Sedláček1, Eva Slaninová1, Stanislav Obruča1

1 Materials Research Centre, Faculty of Chemistry, Brno University of Technology, 612 00 Brno,

Czech Republic, [email protected]

Keywords: polyhydroxyalkanoates, inclusions, stress resistance, crystallization,

Polyhydroxyalkanoates (PHA) are polyesters produced and accumulated by numerous microbial strains in form of granular cell inclusions. Although it is generally accepted that PHA serve primarily as a storage material (source of carbon and energy), it was revealed recently that the PHA granules plays an important surplus role in microbial resistance against various stress factors including temperature (both elevated or cryo) or osmotic shocks, cyclic freezing and thawing and even an UV irradiation [1].

From the material point of view, PHA chains are of a highly hydrophobic nature. Therefore, the granular PHA inclusions need to be separated from the surrounding cytoplasm by an act of surfactants. According to the current view, the surfactant role is filled by the surface layer of granule-associated proteins called phasins. Furthermore, the molecular structure of PHA also results in a high degree of crystallinity of the pure polymer at ambient conditions. However, the intracellularly stored PHA show a totally different material form. The intracellular polymer is amorphous, and therefore the polymer chains remain mobile and flexible. The amorphous state of the polymer is not only of crucial metabolic importance (crystalline PHA are not catabolized by the microorganism), our recent work indicates that it is also directly employed in some of the stress resistance mechanisms [1].

Although the origin of the retained amorphous character of native PHA granules has been debated extensively in the literature, the exact mechanism for how the polymer is protected from spontaneous crystallization in vivo is not yet completely understood. The two main explanations were proposed: i) an involvement of intragranular plasticizers such as water or other low-molecular solutes, and ii) chemical-kinetic mechanism based on a low rate of crystallization in limited volume of sub-micron sized PHA granules.

In our most recent experiments, we have revealed that when some type of stress factors (e.g. elevated temperature, osmotic up-shock, low pH) are applied to Cupriavidus necator H16, PHA granules undergo coalescence (see Fig. 1). Even more surprisingly, wherever the coalescence occurs, the intracellular PHA tend to crystallize in-situ (as revealed by time resolved FTIR analysis), but only after the dehydration of the cell sample (provided by drying the sample at ambient

conditions). These results indicate that both of the above mentioned mechanisms may be involved in retaining the amorphous state. It is likely that application of the stress factor results in coalescence of granules because the surface associated proteins fail to prevent the aggregation of PHA (probably as a result of thermal denaturation of phasins). Nevertheless, the residual water in the granules continues to plasticize the polymer until it is removed by the cell dehydration. Conclusively, the results of these experiments may provide an important contribution to unrevealing the actual way how the PHA is prevent from crystallization in vivo.

Figure 1: TEM photographs of C. necator H16 kept in

aqueous medium at 25°C (top) and 80 °C (bottom)

References [1] OBRUCA, Stanislav, et al. Biotechnology advances, 2018, 36: 856 – 870.

85

Effects of Hydration of Sodium 3-Hydroxybutyrate on Phase

Transitions Connected to Cryoprotectivity Of Microorganisms

Eva Slaninová1, Vitaly Kocherbitov2, Petr Sedláček1, Stanislav Obruča1

1 Materials Research Centre, Faculty of Chemistry, Brno University of Technology, 612 00 Brno,

Czech Republic, [email protected] 2 Biomedical Science, Faculty of Health and Society, Malmö University, SE – 20560 Malmö, Sweden,

Vitaly. [email protected]

Keywords: sodium 3-hydroxybutyrate, cryoprotectant, water activity, phase diagram, DSC

Microorganisms have developed various defense mechanisms to survive against poor living conditions such as low temperature, osmotic shocks, UV exposure etc. For this purpose, they use several ways how to protect themselves (cryoprotectant, membrane channels, chaperones etc.) [1]. Especially, for viability during low temperature, where there is relatively a lot of connected factors such as a cooling rate, ice nucleation and osmotic conditions. Therefore, numerous microorganisms utilize cryoprotectants which have common properties as nontoxicity, low molecular weight, glassy state and easy penetration [2].

In this work, we are focused on cryoprotective mechanisms utilized by bacterial strain Cupriavidus necator H16 which produces and accumulates polyhydroxyalkanoates (PHA) in form of intracellular granules because of storage of carbon and energy and innate ability to protect itself against stress conditions. But intracellular granules do not obtain only PHA, due to metabolism of the PHA where PHA is simultaneously synthesized and degraded, the granules also contain its monomer 3-hydroxybutyrate (3HB) [1].

It is known, that these granules keep amorphous state even at low temperatures. However, it is still unclear why they do not organize themselves to more stable thermodynamic form [1]. There are several hypotheses explaining why hydrophobic granules are in the amorphous state. One of them is based on a small amount of water or monomer sodium 3-hydroxybutyrate which have role as plasticizer which change mechanical properties and structure at the same time. Therefore, we decided to determine the phase diagram of Na 3HB – water system.

Figure 1: Amount of nonfreezing water per gram Na 3HB obtained by DSC data as a function of water content on enthalpy of melting of water.

In our experimental part, we used differential scanning calorimetry (DSC) to observe the glass transitions and separated them into one independent and two dependent regions of phase diagram on water content. Also using the DSC data, we established the amount of nonfreezing water, which was calculated from linear regression (Figure 1) to be approx. 1,22g/g of monomer Na3HB. For determination of sorption isotherms of Na3HB with various content of water, we measured water activity by sorption calorimetry, dynamic vapor sorption and Novasina LabMaster which correspond to data obtained from DSC.

References [1] OBRUCA, Stanislav, et al. Biotechnology advances, 2018, 36: 856 – 870. [2] MAZUR, Peter. American Journal of Physiology-Cell Physiology, 1984, 247.3: C125-C142.

Acknowledgement This work was supported by the project LO1211 and LD15031 of the Ministry Education, Youth and Sports and by the

project GA15-20645S of the Czech Science Foundation (GACR).

86

Light scattering techniques in the study on the formation

of the interactions between polysaccharides and surfactants

Michal Kalina1, Šárka Sovová1, Miloslav Pekař1

1 Brno University of Technology, Faculty of Chemistry, Materials Research Centre, Purkynova

464/118, 612 00, Brno, [email protected]

Keywords: light scattering, molecular weight, particle size, polysaccharide, surfactant, zeta potential

Nowadays, many researchers place great emphasis on polysaccharides and surfactants interactions, especially on oppositely charged ones. It has been widely studied in various fields – food, cosmetics, pharmacy, etc., using different techniques such as NMR spectroscopy, viscosity, surface tension, fluorescence spectroscopy, etc. [1].

Two systems can serve as model system in drug delivery research. Hyaluronic acid (HA) is negatively charged polysaccharide and major constituent of extracellular matrix and can interact with oppositely charged surfactant e.g. cetyl trimethylammonium chloride (CTAB) or carbethopendecinium bromide (Septonex) due to both electrostatic and hydrophobic interactions [2]. In contrast, polycation dextran hydrochloride interacts with sodium dodecyl sulfate (SDS). The knowledge of the conditions at which these systems aggregate into complex as well as their size, molecular weight and stability represent important attributes of any drug delivery system and have been investigated in this work by light scattering techniques [3]. By this reason, primarily, the aggregation concentration for individual studied systems (polysaccharide + oppositely charged surfactant) and optimal polyelectrolyte–to–surfactant ratios for the formation of complex and subsequent gelation into hydrogel were determined using the method of dynamic light scattering (observation of particle size distribution and Z-average particle size of systems) and electrophoretic light scattering (determination of zeta potential). Moreover, the data on the changes in the molecular weight distribution, conformation and distribution of the mass in the complex were determined using the method of SEC-MALS.

The representative outcome from DLS and ELS analysis can be seen in the Figure 1. Basically, the addition of oppositely charged surfactant caused decrease in the absolute value of ZP to zero resulting in the destabilization of the system and rapid increase in measured values of particle sizes. At this point, the system started to aggregate into the complex. Further addition of surfactant resulted in

aggregation and subsequent phase separation of the system (=formation of hydrogel).

Figure 1: The complex formation in the system dextran hydrochloride (concentration 5 g/l) + SDS as was observed by DLS and ELS measurements

The summarization of aggregation concentration (ccrit) determined for individual studied polysaccharide-surfactant systems are listed in Table 1.

Table 1: Summarization of determined aggregation concentrations of individual studied systems

polysaccharide surfactant ccrit 106 (–) HA (MW ≈ 250 kDa) CTAB 150 ± 25 HA (MW ≈ 250 kDa) Septonex 303 ± 36

HA (MW ≈ 1450 kDa) CTAB 145 ± 12 HA (MW ≈ 1450 kDa) Septonex 256 ±22

Dextran hydrochloride SDS 1210 ± 190

The presented contribution provided simple

combination of experimental methods based on light scattering allowing describing the crucial insight on the formation of complex in the system based on hyaluronic acid or dextran hydrochloride and oppositely charged surfactant. These findings are highly important for future modelling of the structure and properties of such complex systems in respect to their applications (e.g. drug delivery).

References [1] DS. Yin, WY. Yang, ZQ. Ge, YJ.Yuan. Carbohydrate Res (2005) 1201-6. [2] L. Petrovic, J. Milinkovic, J. Fraj. Colloid Polym Sci (2017) 2279-85. [3] AK. Agrawal, M. Das, S. Jain. Expert Opin Drug Deliv (2012) 383-402

Acknowledgement This work was supported by project “MRC at FCH BUT – Sustainability and Development” No. LO1211 of the Ministry of

Education, Youth and Sports of the Czech Republic and by the Czech Science Foundation (ProjektNo. 16-12477S).

0.0

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)

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V]

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zero ZP

zeta

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87

Organic Electronics

& Photochemistry and Photocatalysis

88

Modification of Photocatalyst Morphology by Ball-milling and its

Impact on the Physicochemical Properties of Wet Coated Layers

Petr Dzik1, Michal Veselý1, Tomáš Svoboda1

1 Faculty of Chemistry, Brno University of Technology, Czech Republic, [email protected]

Keywords: photocatalyst, morphology, porosity, ball milling, particle size

Ball milling is an efficient method for forced disintegrating of solid materials. In this contribution, we report on the modification of photocatalyst morphology (particle size, porosity, surface roughnes) by this technique and about ist impact on the physical, chemical, electrochemical and photocatalytic properties of layers prepared from the ball-milled material.

For the coating formulation mixing, a recently reported polyorganosiloxane binder[1] was adopted without modification and commercial nanoparticulate titania (Evonik P25) was used as the active catalytic component. The coating formulation was subjected to ball-milling for variable time ranging between 6 hours and 30 days. After the desired ball-milling time was over, it was spin-coated onto soda-lime glass plates producing a titania-polysiloxane hybrid layers. The coated layers were let to dry by spontaneous evaporation and cured by heating at 450 °C for 3 hours which resulted into the oxidative cleavage of the organic moities of the binder and producing tiania-amorphous silica hybrid layers[2].

The properties of both the ball-milled formulations as well as of coated and cured layers were analyzed in detail by numerous techniques involving SEM, AFM, mechanical profilometry, XRD, XPS, ellipsometry, electrochemical methods and their photocatalytic activity was investigated on model compounds.

All the used methods unanimously confirmed, that the ball-milling step, although improvised, induced significant changes in the material. They indicate that the ball milling results in the disintegration of larger titania aggregates which has a significant impact on the properties of coatings. Generally, two types of trends were observed.

Many material properties and layer parameters show monotonous systematic change. For example, the particle size, surface roughness, thickness and haze are all decreasing with increasing milling time.

On the other hand, several other properties, such as specific surface area, photocurrent density and photocatalytic activity show a quite anomalous trend of creating a local maximum (correspoding to appr. 2 days of milling). We believe this strange behaviour is direcly linked to the number and volume of accesible pores in

the layers and is also associated with the way the catalyst aggregates interact with the binder.

100 1000 10000

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%)

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Figure 1: The changes of titania particle size distribution as determined by DLS during ball milling.

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The presented findings clearly illustrate that the

morhologial properties of both bulk and layered catalyst (particle size and distribution, porosity, roughnes) can be to a great extend influenced by mechanical grinding of the parent raw titania. Ball-milling of the coating suspension is surprisingly effective although it took long in this particular case because improvised processing on a lab shaker was employed. Thus by a carefull control of the milling process we can adjust and optimize the performance of immobilized photocatalyst.

References [1] D. Gregori, I. Benchenaa, F. Chaput, S. Therias, J.L. Gardette, D. Leonard, C. Guillard, S. Parola, J. Mater. Chem. A, 2

(2014) 20096-20104. [2] T. Homola, P. Dzik, M. Veselý, J. Kelar, M. Černák, M. Weiter, ACS Appl. Mater. Interfaces, 8 (2016) 33562-33571.

Acknowledgement The work was supported by the Ministry of Interior of the Czech Republic through project VI20162019037.

89

Bioelectronical device for electrostimulation of stem cells

Jiří Ehlich1, Ota Salyk1, Stanislav Stříteský1, Lukáš Omasta1, Eva Šafaříková2, Jan Víteček2, Lukáš

Kubala2, Martin Vala1, Martin Weiter1

1 Faculty of Chemistry, Brno University of Technology, Brno 612 00, Purkyňova 464/118, Czech

Republic 2 Institute of Biophysics AS CR, Královopolská 135, 612 65 Brno, Czech Republic

Keywords: Bioelectronics, electrostimulation, stem cells, PEDOT:PSS, organic semiconductors

Human induced pluripotent stem cells (iPSCs) show the unique ability of differentiation to any cell type within an organism (e.g. neurons, myocytes, bone cells, etc.). Thus they may serve as an excellent tool in regenerative medicine. However the major challenge is to make them differentiate into particular cell line and even then their immature phenotypes limit their therapeutic application in clinical practice.

Current practice capitalizes on mechanical and chemical cues, such as special scaffolds and biochemical factors to facilitate differentiation [1-3]. Recently it has been shown that electric stimulation may promote stem cell differentiation into electrogenic cell types such as neurons and cardiomyocytes [1-3]. However the inorganic materials known for not ideal biocompatibility were used as electrodes for electrostimulation and there was no clear clue between the electrostimulation pattern and the outcome of differentiation [1-3].

Our work tries to determine whether electrical stimulation of various voltage, current and frequency in combination with various organic semiconductors used as electrodes could influence the differentiation and maturation of mouse induced pluripotent stem cells to other types of cells.

The prototype biolectronical device for electrostimulation is be presented. The device is initial platform for testing various organic semiconductors based on poly(3,4-ethylenedioxythiophene) (PEDOT) with various counter anions such as polystyrene sulfonate (PSS), hyaluronic acid (HA) etc. with chemically modified surfaces in respect to biocompatibility [4].

Device is able to apply electric fields to tested iPSCs in various modes. Premature results of baseline iPSCs electric stimulation will be also presented.

References [1] Hernandez D., Millard R., Sivakumaran P., et al., Stem Cells int., (2016) p. 1718041 [2] Chan Y.C.., Ting S., Lee Y.K., et al., J. Cardivasc. Transl. Res., (2013) 6(6): p. 989-999 [3] Yamada M., Tanemura K. Okada S., et al., Stem cells, (2007). 25(3): p. 562-570 [4] Šafaříková E. et al, Sensors and Actuators B 260 (2018) p. 418–425

Acknowledgement This work was supported by Czech Science Foundation via project No. 17-24707S, research infrastructures was

supported by projects MŠMT No. LO1211, and by the Faculty of chemistry BUT under project No. FCH-S-17-4685.

90

Improvement of Performance of Screen-Printed Electroluminescent

Device by Reducing the Thickness of Dielectric Layer

Michal Hrabal1, Petr Dzik1, Lukáš Omasta1, Martin Vala1, Martin Weiter1

1 Materials Research Centre, Faculty of Chemistry, Brno University of Technology, Purkyňova

464/118, 612 00 Brno, Czech Republic

Keywords: Powder-Based Electroluminescence, Screen printing, Dielectric

Electroluminescence (EL) in general is a phenomenon where electric field excites molecules into higher energetic state and a light is generated upon return of the molecule into a ground energetic state. The electroluminescence in inorganic materials is divided into two distinctive branches based on the specific physical process leading to generation of light: injection EL and high-field EL which is further divided to thin-film EL and powder-based phosphor EL working under both direct current and alternating current. Figure 1 shows the alternating current powder-based electroluminescent panels (ACPEL) which is the topic of this work.

Figure 1 A photo of a patterned large area ACPEL panel

Powder-based phosphor luminescence is currently the only technique suitable for manufacturing of large area patterned structures by the means of simple printing techniques. Interesting feature of devices based on this technique is their potential flexibility since they can be printed on either solid glass substrates or various plastic foils. This ability is in contrast to thin film EL devices which are being manufactured by sputtering on solid substrates. Screen printing is the most suitable technique for printing of the above mentioned devices because of the typical viscosity and density of inorganic printing formulations and because of the ability to prepare patterned layer.

Typical printed ACPEL panel consists of 4 layers which is shown on Figure 2.

Figure 1 Architecture of panel

The first layer (1) is plastic foil/glass substrate with transparent bottom electrode; second layer (2) is phosphor (doped ZnS); third layer (3) is dielectric (BaTio3)

and topmost layer (4) is top electrode. All the layers printed by screen printing show the same trait – thickness in the order of tens of microns. This is somewhat problematic because applied AC voltage needed for generation of light is in the order of hundreds of volt which is both hazardous for human health and cost effective.

One way to decrease the driving voltage is to decrease the thickness of dielectric layer. A series of samples with varying thickness (1 layer is approximately 12 microns thick) of dielectric was prepared and the spectral irradiance of emitted light was taken. Conditions of the driving alternating voltage were set as 250 V and frequency 1600 Hz and were constant for each panel. Spectral characterization of panel can be seen in Figure 3. It is clear that thinnest layer shows increase of the irradiance of panel by almost 25 %. Interestingly the samples with thickness from ~ 20 to 50 microns show exactly the performance

Figure 2 Normalized spectral irradiance of panels with varying thickness at 250 V.

It was shown that the downsizing of dielectric layer effectively leads to improving the power of light emitted by the panel. It is however impossible to prepare thinner layers thanks to the size of grains of dielectric. The main goal of this work is to prepare and characterize a panel based on inkjet printing formulation of sub-micron grains of dielectric. The reduction of size of particles is achieved by the mean of mechanical milling of clusters of 20 %mass suspension of fine powder BaTiO3 in dowanol PM and preventing their re-aggregation by various means. The size of BaTiO3 is determined by the dynamic light scattering method (DLS).

Acknowledgement This work was supported by Czech Ministry of Trade

and industry via project no. FV 10278, research infrastructure was supported by project MŠMT No. LO1211 from the National Programme for Sustainability I (MEYS CR)

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91

Printed Perovskite Solar Cells with Carbon Back Electrode

Matej Hvojnik, Michal Hatala, Barbora Krištofovičová, Pavol Gemeiner, Milan Mikula

Department of Printing Arts Technology and Photochemistry, Faculty of Chemical and Food

Technology SUT in Bratislava, Radlinského 9, 821 37, Bratislava, Slovakia

[email protected]

Keywords: perovskite solar cell; mesoporous oxide layers; carbon back electrode; screen printing

Organometal trihalide perovskite solar cells (PSCs) have been much enhanced in the past few years as an interesting alternative due to their simple and low-cost solution-processed fabrication techniques. Many varia-tions of PSCs were found to improve preparation process, efficiency and stability. Among them, carbon-based C-PSCs without hole transport materials [1] seem to be very promising for the stability because carbon materials are stable, water-resistant and inert to ion migration from perovskite and electrodes.

C-based systems use mesoporous oxide (TiO2) electrodes and porous scaffold space and separating layers (Al2O3, ZrO2) through which the perovskite precursores are infiltrated. The system originates from dye sensitized solar cell (DSSC) where mesoporous layers were standardly printed with nano-oxide pastes [2] and where also C-based materials including conductive polymers and nanotubes were used as counter-electrode [3].

Figure 1: Carbon based perovskite solar cell structure

In this work printable perovskite cells with C-based back electrode were prepared using low-temperature and high-temperature processes of mesoporous oxide layers application and using different hole blocking compact TiO2 layers. Oxide layers were screen printed and carbon layers doctor bladed. Moreover, the functionality of the cells prepared with our pastes is compared with the cells prepared with commercial pastes from Solaronix.

For perovskite infiltration we used both one step (commercial layers) and two-step methods with different

variations to achieve the best conversion of precursors to perovskite. The individual layers were characterized by microscopic and spectroscopic methods and the conversion efficiency of solar to electric energy was determined measuring photocurrent-voltage load characteristics under 1000 W/m

2 of standard day light

exposition.

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References [1] H. Chen, S. Yang, Advanced Materials (2017) 1603994 [2] P. Gemeiner, M. Mikula, Materials Science in Semiconductor Processing 30 (2015) 605-611 [3] P. Gemeiner, J. Kuliček, M. Mikula, M. Hatala, Ľ. Švorc, L. Hlavatá, M. Mičušík, M. Omastová, Synthetic Metals 210

(2015) 323–331.

Acknowledgement The authors thank for financial assistance from the Slovak Grant Agency, VEGA 1/0900/16 and Development Agency under the contract APVV-15-0460.

FTO-glass

BL mp-TiO2 space layer

Perovskite infiltration

C-back el.

FTO


92

Optoelectronic control of single cells using organic photocapacitors

Marie Jakešová1, Malin Silverå Ejneby2, Tony Schmidt3, Johan Brask2, Vedran Derek1, Magnus

Berggren1, Rainer Schindl3, Fredrik Elinder2, Daniel Simon1, Eric Daniel Głowacki1

1 Laboratory of Organic Electronics, ITN Campus Norrköping, Linköping University, 60221,

Norrköping, Sweden, E-mail: [email protected] 2 Department of Clinical and Experimental Medicine, Linköping University, SE-58185, Linköping,

Sweden 3 Institute for Biophysics, Medical University of Graz, Harrachgasse 21/IV, 8010, Graz Austria

Keywords: photocapacitor, electrophysiology, photostimulation

Light-mediated control of electrophysiology at the single cell level is a powerful tool for basic research and enabling novel biomedical technologies. Herein we report on organic electrolytic photocapacitors (OEPCs)[1], a thin-film semiconductor optoelectronic device that transduces optical light pulses into transient potentials in electrolytes. The devices consist of a semi-transparent conductor layer covered with metal-free phthalocyanine, and N,N’-dimethyltetracarboxylic bisimide, which function as the electron-donor and electron-acceptor layers, respectively. This metal/donor/acceptor stack produces an open circuit potential in electrolyte solution of 300 mV upon illumination using light in the NIR tissue transparency window 630-680 nm. We have performed single-cell electrophysiological recordings on xenopus

laevis oocytes, as well as human embryonic kidney cells, finding photoinduced changes of membrane potential on the order of tens to hundreds of millivolts. The magnitude and duration of the transient voltage induced across the membrane depends on the light intensity used, the capacitance of the back electrode and the waveform of the light pulse. We find also photoinduced shift in the i-v characteristics of voltage-gated ion channels enabling their opening at more negative potentials, which is ultimately important for determination of action potential triggering mechanism. The amplitude and time window of transient voltages accessible is appropriate for a wide degree of electrophysiological control of single cells.

References [1] D. Rand, M. Jakešová, G. Lubin, I. Vėbraitė, M. David‐Pur, V. Đerek, T. Cramer, N. S. Sariciftci, Y. Hanein and E. D.

Głowacki, Advanced Materials (2018) DOI: 10.1002/adma.201707292

93

Implementation of polycyclic cycloalkane systems: a path to high-

performing, soluble, versatile and sustainable organic

semiconducting materials

Alexander Kovalenkoa, Cigdem Yumusakb, Patricie Heihrichovaa, Stanislav Striteskya, Martin Valaa,

Martin Weitera Niyazi Serdar Sariciftcib and Jozef Krajcovica,

a Brno University of Technology, Faculty of Chemistry, Materials Research Centre, Purkyňova 118,

612 00 Brno, Czech Republic. b Johannes Kepler University Linz, Linz Institute for Organic Solar Cells (LIOS)/Institute of Physical

Chemistry, Altenbergerstraße 69 4040 Linz, Austria.

Soluble organic semiconducting materials have a

particular application potential for easily processed low-cost organic electronics devices. Solubility of organic pi-conjugated small molecule derivatives, such as diketopyrrolopyrroles (DPPs), indigos, epindolidiones, squaraines and many other, is usually attained by a side-chain alkyl substitution, which is meant to interrupt inter- and intramolecular H-bonds. Due to these bonds insoluble organic semiconducting materials are usually more stable; moreover as a result of tight aggregation of

-conjugated cores through intermolecular H-bond insoluble materials have shown remarkable thermal stability as well as high charge carrier mobilities for both electrons and holes [1]. However insolubility brings its obverse case: such materials are difficult to purify and they can’t be deposited by coating or printing techniques, which is a promising way towards cheap production organic electronics.

In this work, we offer a strategy to synthesize thermally stable and soluble high-performing materials for a wide range of organic electronics applications. The crucial component of the present approach is using adamantyl substitutions in solubilization side-groups.

Ability of adamantane molecule to self-organize into crystals with unusually high melting point was used to

reinforce packing of -conjugated dyes in the solid state. As a result materials with adamantyl containing side-chains possess superior electrical and optical properties, and at the same time high thermal stability. Abovementioned side chain can improve solid-state fluorescence quantum yields of the materials [2] and significantly increase the melting point. Considering electrical properties, soluble DPP derivative with ethyl-adamantyl solubilization side-groups showed abmipolar behavior with both hole and electron mobilities higher than the insoluble analogue. How it

was confirmed by XRD analysis a distance between -conjugated cores is shorted than the one of insoluble material due to adamantyl-adamantyl aggregations, which resulted in high charge carrier mobilities. It has to be added that this approach can be applied for a large portfolio of the organic dyes (indigos, epindolidiones, squaraines, oligothiophenes etc.), where solubility can be reached by a side-group substitution [3].

References [1] E. Głowacki et. al., Advanced Functional Materials 25(5), 2014, DOI: 10.1002/adfm.201402539; [2] J. Krajčovič et. al., Journal of Luminescence 175, 2016, DOI: 10.1016/j.jlumin.2016.02.019 [3] A. Kovalenko et. al., J. Mater. Chem. C, 2017,5, 4716-4723, DOI: 10.1039/C6TC05076J

94

Alkyl substitutions a powerful tool for tailormade properties of

soluble and versatile organic semiconducting materials

Jozef Krajčovič1, Alexander Kovalenko1, Martin Vala1, Martin Weiter1, Cigdem Yumusak2, Niyazi

Serdar Sariciftci2

1 Brno University of Technology, Faculty of Chemistry, 612 00 Brno, Czech Republic,

[email protected] 2 Linz Institute for Organic Solar Cells (LIOS), Johannes Kepler University Linz, Austria

Keywords: organic semiconductors, adamantane substitutions, solubilizing side chains

Nowadays many organic semiconductors have been developed to improve the device performance, where most of the efforts focused on the design and synthesis of new π-conjugated backbones [1]. However, much less efforts have been devoted to understanding the role of the side chains of organic semiconductors. Alkyl chains, oligo (ethylene glycol) chains, and fluoroalkyl chains are three commonly used side chains in organic semiconductors. These side chains generally do not directly contribute to charge transport in organic semiconductors and are usually used as solubilizing groups.

Adamantane is the simplest diamondoid and possesses exceptional physical properties. Moreover, adamantane is more stable saturated hydrocarbon isomer of such a small molecular weight.

Ethyl-adamantyl side groups substituted on to para-bis(2-thienyl)phenylene, a solid-state fluorescent dye, were found to induce π–π interactions between the conjugated para-bis(2-thienyl)phenylene cores. At the same time, stacking between the central unit and the adamantyl-containing side group was observed. As a result, due to steric hindrance augmentation of the solid-state, luminescence was observed. Moreover, substitution of standard alkyl side chains with ethyl-

adamantyl groups resulted in raising the melting point temperature from 55 °C to 250 °C [2].

Figure 1: XRD structure of ethyl-adamantylalkylated para-bis(2-thienyl) phenylene

Novel ethyladamantyl solubilization side groups were found as adamantyl–adamantyl stacking in soluble diketopyrrolopyrrole (DPP) derivatives. Due to high crystallinity and co-planarity electron transfer was preserved with a mobility of 0.2 cm2/(V s) for dithiophene-DPP [3].

References [1] C. Wang, H. Dong, W. Hu, Y. Liu, D. Zhu, Chem. Rev. 112 (2012) 2208. [2] J. Krajčovič, A. Kovalenko, P. Heinrichova, M. Vala, M. Weiter, Journal of Luminiscence. 167 (2016) 222 [3] A. Kovalenko, C. Yumusak, P. Heinrichova, S. Stritesky, L. Fekete, M. Vala, M. Weiter, N.S. Sariciftci, J. Krajčovič, J.Mat.Chem. C. 5 (2017) 4716

Acknowledgement This work was supported by the Czech Science Foundation, Czech Republic via Project No.13-29358S, project FCH-S-18-5331 and Project MŠMT, Czech Republic No. LO1211

95

Conductive polymers integrated into a textile matrix designed for

sensor elements

Kubáč, L., Pretl, S., Josefík, F., Martinková, L., Hamacek, A.

Centre for Organic Chemistry Ltd., Rybitví 296, 533 54, Czech Republic

University of West Bohemia in Pilsen, Faculty of Electrical Engineering, Univerzitní 26, 306 14 Plzeň,

Czech Republic

Inotex Ltd., Štefánikova 1208, 544 01, Dvůr Králové n.L., Czech Republic

Keywords: conductive polymers, textile, sensor

Textile materials, yarns and fabrics, have been permanently modified by conductive polymers. The procedure was verified in pilot scale with two materials, PEDOT and Polypyrrol. The described process of modification of textile materials by conductive polymers has enabled their use in electronic applications. In addition to the possibility of the charge transfer or resistance heating of the modified fabric, it has been shown that the material can also be used for sensor purposes. Reproducible responses showed the following sensors:

- The temperature sensor has a reproducible response in a temperature range of 10 to 90 °C. The resistance of the modified yarn decreases with increasing temperature.

- The pressure sensor is designed as a three-layer system acting as a switch when a defined change in external pressure is exceeded.

- Fabric maintenance sensor. Sensor reproducibly shows violation of prescribed maintenance procedures for textile materials, which are equipped with special surface treatments sensitive to some types of laundry.

96

Time-resolved kinetics of excitons, polarons and polaron pairs in

organized thin films of conducting polymers

Miroslav Menšík1, David Rais1, Jiří Pfleger1, Petr Toman1

1 Institute of Macromolecular Chemistry, ASCR, Department of Polymers for Electronic and

Photonics, Heyrovského nám. 2 162 06 Prague 6 Czech Republic, [email protected]

Keywords: transient absorption spectroscopy, excitons, polarons, conducting polymers, P3HT

A study of time-resolved kinetics of excitons and polarons in organized thin films of conducting polymers after photoexcitation provides important insight for the construction efficient optoelectronic devices.

It was shown recently that after photoexcitation of 10 nm thick thin films of regioregular poly(3-hexyl-thiophene) (rr-P3HT) singlet excitons are created first, and then, within ca 200 fs the hot inter-chain polaron pairs (PP) are formed. Only later, on a time-scale of ca 2-3 ps polarons (P) are formed [1].

The population of excitons has shown a power-law

decay ~𝑡−0.5, which was explained by the exciton-exciton collision controlled by a 1-d diffusion of excitons along polymer chains in crystalline-like domains of P3HT. Next, it was observed that by addition of gold nanoparticles atop of the polymer layer the diffusivity of excitons increased due to the phonon waves travelling along those polymer chains emitted by heated gold nanoparticles [1].

The decay kinetics of PP undergoes two different kinetic regimes. First, in the subpicosecond time scale the hot PP decay by a coherent up/down conversion process, while one of the bound counter-charges of the inter-chain PP hops coherently to another parallel polymer chain [2]. As the mutual distance of the counter-charges increases to a doubled inter-chain spacing the charges are detected in the pump-probe experiment as “free” P. The initial formation of “free” P states was directly correlated with the decay of PP [2]. Next, mathematical analysis of time-resolved absorption spectra of this coherent regime clearly proved the Fermionic nature of the excited species. On the other hand, PP thermalize within few ps after photoexcitation, and provide by a power-law decay ca ~ 𝑡−0.4, pointing to a bi-molecular collision process of the inter-chain PPs with 1-D diffusion controlled kinetics.

Contrary to PPs the time-resolved spectra of P states

showed significantly slower decay of ca ~ 𝑡−0.25 [1], which was slower than predictions by models of diffusion controlled collision processes with time-independent diffusion coefficients.

Therefore, we introduced the concept with time-dependent diffusion coefficient and elaborated a method of its determination from transient absorption spectra of decay kinetics of photoexcited species controlled by the collision processes [3].

Our method can be directly utilized for arbitrary systems with the collision decay process controlled by the diffusion of photoexcited species.

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References [1] D. Rais, M. Menšík, B. Paruzel, D. Kurunthu, J. Pfleger, Phys. Chem. Chem. Phys. 19 (2017) 10562. DOI: 10.1039/c7cp00286f [2] M. Menšík, J. Pfleger, P. Toman, Chem. Phys. Lett. 677 (2017) 87. DOI: 10.1016/j.cplett.2017.03.082 [3] M. Menšík, J. Pfleger, P. Toman, Chem. Pap. (2018) in press. DOI: 10.1007/s11696-018-0439-1

Acknowledgement This work is supported by the project LTC17029 of the Ministry of Education, Youth and Sports of the Czech Republic

under COST Action MP1406.


97

Screen Printed Biocompatible Photoresist as a mean to Enhance

Performance of Organic Electrochemical Transistors

Lukáš Omasta1, Jiří Ehlich1, Stanislav Stříteský1, Michal Hrabal1, Ota Salyk1, Martin Vala1, Martin

Weiter1, Milan Matejka2

1 Materials Research Centre, Brno University of Technology, Purkyňova 118, 612 00 Brno, Czech

Republic, [email protected] 2 Institute of Scientific Instruments of the Czech Academy of Sciece, Královopolská 147, 612 64

Brno, Czech Republic

Keywords: organic electrochemical transistor, PEDOT:PSS, photoresist SU-8, printed electronics,

screen printing, photolithography

Human cell cultures provide a potentially powerful means for pharmacological and toxicological research. Various microplate patterns and configurations with a multielectrode array of organic electrochemical transistors (OECTs) based on the semiconductive polymer poly(3,4-ethylenedioxythio-phene):poly(styrene sulfonic acid) PEDOT:PSS was developed and fabricated using conventional printing methods (inkjet printing, screen printing) together with standard lithographic procedures. The devices were designed for electrogenic cell monitoring and stimulation [1].

In good agreement with previously published works improvement of the transconductance and time constant of prepared devices can be achieved by decreasing the OECT dimensions [2]. This is done by shortening the gate-channel distance and minimizing the channel-electrolyte charge electrical double layer (EDL) capacitance by reducing the channel area.

Figure 1: OECT microplate for electrogenic cells cultivation and investigation together with power source and signal amplifier

Further miniaturization and optimization were done via photolithography. To this end we used commercially available biocompatible photoresist SU-8. This is an epoxy-based negative photoresist commonly used in the printed circuit board (PCB) industry.

In this study the screen printing process was optimized and layers of 30 μm thick SU-8 and photolithographically produced patterns with a resolution better than 50 μm were prepared. This layer was intended as a mask to cover underlying screen printed electrodes and active layer of PEDOT:PSS which together formed the OECT array. Output, transfer and transient characteristics of prepared devices were evaluated. The transconductance up to 8 mS and the time constant of 20 ms was measured.

Figure 2: SEM pictures of prepared photolithographic layer of SU-8

References [1] Salyk, O., Víteček, J., Omasta, L., Šafaříková, E., Stříteský, S., Vala, M., Weiter, M. Organic electrochemical transistor microplate for real-time cell culture monitoring. Applied Sciences – Basel 10, 998–1008 (2017) [2] Stříteský, S., Marková, A., Víteček, J., Šafaříková, E., Hrabal, M., Kubáč, L., Kubala, L., Weiter, M., Vala, M. Printing inks of electroactive polymer PEDOT:PSS: The study of biocompatibility, stability and electrical properties. Journal of Biomedical Materials Research: Part A (2018) in review

Acknowledgement This work was supported by Czech Science Foundation via project No. 17-24707S, research infrastructures was

supported by projects MŠMT No. LO1211 and J. Ehlich was supported by the Faculty of chemistry BUT under project No. FCH-S-17-4685.

98

High-k dielectrics for organic electronic devices

Jiří Pfleger, Francesco Piana, Bartosz Paruzel, Yadu Ram Panthi

Institute of Macromolecular Chemistry, Czech Academy of Sciences, Polymers for electronics and

photonics, Heyrovský Sq. 2, 162 06 Prague 6, Czech Republic, e-mail: [email protected]

Keywords: Charge transport, OFET, Dielectrics, Polymer composites, Organic electronics

The functionality of many electronic components like field effect transistors or electronic memories relies on the capability of a charge accumulation. High capacity can be achieved by decreasing thickness of the dielectric layer which, however, brings problems for printing technology. Increasing the dielectric constant is then the only possibility how to achieve a high capacity of electronic components. High dielectric constant is often achieved by introducing polarizable chemical groups, which often increase dielectric losses and leakage current due to introduced ionic conductivity. The polarization of permanent dipoles reflects also the relaxation of the polymer, which leads to hysteresis of current-voltage characteristics. Ions and dipoles present in the dielectrics can affect the transport of charges in the semiconductor by charge trapping on localized states created in the semiconductor by electrostatic interactions.

In our work we focused on poly(2-cyanoethyl vinyl

ether), CEPVA, a polymer known for its high value of dielectric constant. CEPVA is a commercially available polymer commonly prepared by cyanoethylation of polyvinyl alcohol [1]. It is well soluble in DMF and similar solvents, amorphous in solid state with a low Tg around 19 °C and dielectric constant ε’ ~ 15. Broadband dielectric

spectroscopy showed -relaxation in temperatures well

below Tg caused by the rotation of side groups and -

relaxation around and above Tg due to the increased segmental motion. We show how to influence dielectric properties of this polymer by blending, crosslinking and combining with high-k inorganic filler.

Crosslinking with several curing agents was tested. Concerning Tg, suberoyl chloride (SU) had almost no effect, while all other crosslinkers shifted it markedly to higher temperatures, particularly (hexafluoroiso-propylidene)-diphthalic anhydride (HDA) with Tg over 100 °C. On the other hand, TGA showed that CEPVA crosslinked with ethylenediaminetetraacetic dianhydride (EAD) provided the best thermal stability. The dielectric spectroscopy showed that SU and HDA crosslinkers suppressed the side chain movements corresponding to the β-relaxation. The α-relaxation was instead reduced and shifted to higher temperatures as the effect of the reduced movement freedom of the crosslinked polymer. EAD was the crosslinker, which offered the best compromise between the decrease of ε’ and its thermal stability. In the case of SU; HCl release and secondary reactions with the nitrile and ether groups during the film preparation leaded to low Tg and low dielectric performance.

By blending CEPVA with poly(methyl methacrylate) (PMMA) Tg increased up to 29 – 30 °C and dielectric constant to ε’ ~ 27 (104 Hz) with 30 wt.% of PMMA fraction. Over this concentration a phase separation occurs, which drastically affects the morphology of the films. The increase of ε’ above the values typical for both pure component of the blend has been attributed to the effect of PMMA on the chain rearrangement during the evaporation of the solvent but the exact mechanism is yet not clear.

We exploited CEPVA and crosslinked CEPVA as a gate dielectrics in OFETs with TIPS-pentacene The hysteresis caused by polarization and/or trapping was detected. It was also found that the residual hydroxyl groups form hydrogen bonds which stabilize a polymer network and limit nitrile groups mobility. The mutual dipole-dipole interactions lead to a quasi-ordered structures of associated dipoles, which may not only improve a charge carriers accumulation but also limit concentration of deep surface traps.

References References. 1. X. Li, S. H. Goh, Y. H. Lai and S. M. Deng, Journal of Applied Polymer Science 1999, 73, 2771-2777.

Acknowledgement This work was supported by the Grant Agency of the Czech Republic (Project No. 17-03984S)

99

Organic Solar Cells with an Inkjet Printed Hole-Extracting Graphene

Oxide Layer

Jan Pospisil1, Alexander Kovalenko1, Oldrich Zmeskal1, Martin Vala1

1 Brno University of Technology, Faculty of Chemistry, Purkynova 118, 612 00 Brno, Czech Republic,

[email protected]

Keywords: organic solar cells, graphene oxide, reduction, current-voltage measurement, impedance

spectroscopy

Graphene, graphene oxide (GO) and its reduced form

are very promising materials with excellent optical and electrical properties. It has been reported, that a high-quality single- or multilayer graphene, a very attractive candidate for electronic applications, can be produced by a chemical vapor deposition method on metallic surfaces [1]. However, this results in limitation of the substrate materials. Nowadays, it is possible to obtain solution-processable graphene oxides from exfoliation of graphite powders with strong acids or oxidizing agents (Hummer´s method etc.). Functionalization of graphene allows tune up chemically its optoelectronic properties while maintaining the good dispersibility in water and other polar organic solvents [2]. Another promising opportunity is a use of graphene oxide with a consequent reduction. Unfortunately, reducing the GO cannot result in completely pure graphene, however, the big advantage may be that by using a variety of reducing reagents can be selected own C/O ratio (reduction rate of the GO layers can tune up its work function) [3].

Nowadays there is a really need to study, among others, the new hole-transport materials for organic solar cells, especially for perovskite solar cells. Current perovskite solar cells use mostly spiro-OMeTAD, which is really expensive and the homogeneity of final layer is also another problem. In this regard, an another frequently used material PEDOT:PSS (in organic solar cells and also in perovskite solar cells with inverted architecture) is also not appropriate due to its hygroscopic nature and most materials, especially perovskite materials, are very sensitive to humidity. Of course, the material used as a hole transport layer must be highly transparent [4].

In this regard, this paper deals with the study of light conversion efficiency of organic photovoltaic cells with an inkjet-printed graphene oxide layer. The graphene oxide is used in this experiment as a hole-extracting, electron blocking layer in bulk heterojunction organic solar cells based on diketopyrrolopyrrole:fullerene blend. It is also studied the influence of graphene oxide reduction (chemically, by UV radiation and by annealing) on the efficiency of photovoltaic conversion. Power conversion efficiencies and the transport of charge carriers are evaluated by measuring of current-voltage characteristics and mainly by impedance spectroscopy analysis (see Figure 1, Cole-Cole diagrams) [5]. It is clear, from Figure 1, that the use of graphene oxide and its reduction play a significant role in the final structure of prepared solar cells.

Figure 1: The influence of hole-extracting GO layer and its reduction on dark and light Cole-Cole diagrams (in log-log scale) in comparison with reference cell (with PEDOT:PSS)

References [1] A. K. Geim, K. S. Novoselov, Nature Materials 6 (2007) 183. [2] W. Chen, L. Yan, P. R. Bangal, Carbon 48, 1146 (2010). [3] S. Pei, H.-M. Cheng, Carbon 50 (2012) 3210. [4] J. Liu, M. Durstock, L. Dai, Energy & Environmental Science 7 (2014) 1297. [5] G. Garcia-Belmonte, A. Munar, E. M. Barea, J. Bisquert, I. Ugarte, R. Pacios, Organic Electronics 9 (2008) 847.

Acknowledgement Authors thank to Ministry of Education, Youth and Sports of Czech Republic for support by project Sustainability and

Development REG LO1211 addressed to Materials Research Centre at FCH BUT.

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100

Flashing light at the “dark” triplet states in organic semiconductors

David Rais,1 Jiří Pfleger,1 Petr Toman,1 Miroslav Menšík,1 Yaduram Panthi,1 Martin Vala,2 Jozef

Krajčovič,2 Stanislav Stříteský,2 Martin Weiter2

1 Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovského

nám. 2, 162 06, Prague, Czech Republic, [email protected] 2 Materials Research Centre, Brno University of Technology, Purkyňova 118, 612 00 Brno, Czech

Republic.

Keywords: intersystem crossing, singlet fission, triplet exciton, transient absorption

The triplet (high-spin) excitons play key role in photophysical processes occurring in the organic materials. It stems from the uniquely long lifetime of the triplets dictated by the weak spin-orbit coupling together with spin-forbidden transition to the ground state. Their management plays a key role not only in the industry to achieve high external quantum yield of electroluminescence in current commercial organic light-emitting devices [1], but also at much larger scale in the nature – e.g. for photo-protection in plants [2].

In the present work we focus on the phenomenon of singlet fission (SF) – generation of a pair of triplet excitons (2T1) out of one photogenerated singlet exciton (S1) in organic semiconductors:

2S0 + hν → S0+S1 → 1(TT) → 2T1

Figure 1: Ultrafast singlet fission in in a metallo-supramolecular polymer.

It was envisaged as a way to increase the theoretical limit of energy conversion in solar photovoltaic cells [3], since both triplets can possibly undergo a charge separation and thus contribute the photocurrent with two charge carriers instead of only one.

Using time-resolved transient absorption and fluorescence spectroscopies to probe the photophysical processes, we identified fast singlet fission in a metallo-supramolecular polymer [4] formed by the coordination of Zn

2+ ions to bis(terpyridine-4′-yl)terthiophene ligand

(Fig. 1). In this case, since S1 is energetically lower than the coupled triplet-pair state, the system requires photoexcitation to the next optical state (Sn) in order to

be able to access the intermediate 1(TT) state and fission

into two triplets (2T1). The zinc-supramolecular polymer exhibits relatively short lifetimes for the fission triplets due to triplet−triplet recombination, as is commonly observed in polymers.

Our effort to expand the basis of SF materials continues with synthesis of two derivatives of 3,6-di(thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (TDPP), inspired by the recently reported derivative of diketopyrrolopyrrole showing triplet yield in excess of 100% [5]. By varying the thin film preparation method, we influenced the resulting rate constant for triplet formation (Fig. 2). We observed behavior that is consistent with the SF phenomenon, i.e. decreasing rate with increasing energy difference |E(S1)–2E(T1)| [3]. However, triplet yield quantification resulted in large uncertainties. Therefore, the production mechanism of the triplet excitons remains equivocal.

Figure 2: The triplet exciton (T1) formation rate depends strongly on the position of absorbance peak in the solid thin film. The film processing: VD – vapor deposition; SA – solvent annealing; SC – spin-coating.

References [1] M. Baldo, et al., Nature 395 (1998) 151. [2] A. Ruban, et. al., Nature 450 (2007) 575. [3] M. Smith, and J. Michl, Chemical Reviews 110 (2010) 6891. [4] D. Rais, et. al., J. Mater. Chem. C 5 (2017) 8041. [5] C. Mauck, et al., J. Am. Chem. Soc. 138 (2016) 11749.

Acknowledgement The work was supported by the Czech Science

Foundation, grant No. 17-02578S, and the Technology Agency of the Czech Republic (Project No. TE01020022).

101

New bio-inspired organic semiconductors for bio-organic electronics

Jan Richtar1, Alexander Kovalenko1, Martin Weiter1, and Jozef Krajčovič1

1 Brno University of Technology, Faculty of Chemistry, Purkyňova 118, 612 00 Brno, Czech Republic,

[email protected]

Keywords: flavines, bio-inspired materials, charge transport

Biologically inspired molecular engineering is a promising way towards green, cheap, bio-compatible, non-toxic and versatile materials for future bio-organic semiconductor science and technology. In addition, ability to tune molecular structure allows improving stability and performance of the original material. Flavines are known to be extremely versatile, thus enabling the path to the innumerous modification in order to obtain the desired properties. Diimide highly extended π-conjugated structure produce strong π−π and hydrogen-bonding intermolecular interaction and the controllable physicochemical properties by introducing a variety of alkyl chains on the N-position in diimide group [1]. New series of flavines contained fused or non-fused aromatic moieties were synthetized by using novel synthetic approaches.

Careful selection of aromatic moieties allows for

increasing the electron-accepting ability through the expansion of the π-system, enhancing charge transport properties and thermal stability.

We demonstrate the simple synthetic methodologies

for preparation of flavines compounds possessed high thermal stability and chemical versatility, which indicated their potential as a building block in the future (e.g. as co-polymer or metal-organic complexes). Fine tailoring of the structure by expanding the π-system afforded us derivatives with progressive light-absorption up to 700 nm and thermal stability reaching 420°C

References [1] S. Vasimalla, S.P. Senanayak, K.S. Narayan, Chem. Mater., 26 (2014) 4030.

Acknowledgement This work was supported by the Czech Science Foundation grant No. 17-24707S and by project no. FCH-S-18-003.

102

Charge Carrier Mobility in Lamellar Structure of Conjugated

Polymers

Petr Toman, Miroslav Menšík, Jiří Pfleger

Institute of Macromolecular Chemistry, Czech Academy of Sciences, Polymers for electronics and

photonics, Heyrovský Sq. 2, 162 06 Prague 6, Czech Republic, e-mail: [email protected]

Keywords: Charge mobility; Conjugated polymer; Charge transport modelling; Field effect transistor

Conjugated polymers belong to widely used functional materials for different applications in electronics and photonics. Thus, the detailed knowledge of the charge transport mechanism and relations between molecular and macroscopic properties of these materials is very important. While various previously used approaches based on analytic forms of the density of states have been successful as satisfactory phenomenological models with just a few empirical parameters, they are obviously incorrect on the molecular-scale level, namely due to their failure to properly describe delocalized on-chain charge carrier states in conjugated polymers and corresponding density of states. Strong dispersion forces between building blocks of many conjugated polymers lead to a chain packing into a lamella and subsequent ordering of lamellas into nanofibers with a typical width of several tens of nm (see Figure 1).

Figure 1: Polymer chains packed into lamellas forming a nanofiber with a typical width about 20 nm.

Chain folding usually limits the on-chain charge carrier motion to the nanofiber width. Consequently, the charge carrier transport in the nanofiber proceeds by the charge carrier hopping among conjugated chain segments in an essentially two-dimensional space. Since most conjugated polymers are hole-transporting materials, our

model is limited to the hole transport only. A unique feature of our molecular-scale approach is combination of the quantum mechanical description of the on-chain hole states with a semi-classical (Marcus) solution of the inter-chain hole hopping. Numerical solution takes into account many delocalized hole states on each conjugated chain segment, which are occupied according to the Fermi-Dirac distribution.

Our hole mobility model was used for simulation of the charge transport in an active layer of the organic field-effect transistor (OFET), namely dependences of the mobility on the energetic disorder, hole concentration, and the longitudinal (between source-drain) and transverse (gate) electric field were calculated [1,2]. Results show that, depending on the degree of the energetic and structural disorder, the hole mobility increases significantly with increasing charge concentration due to trap filling. At high charge carrier concentrations, the effect of the energetic disorder disappears and the mobility decreases slightly due to the lower density of unoccupied states available for the hopping transport. It could explain the experimentally observed mobility degradation in organic field-effect transistors at high gate voltage. While deviations of the longitudinal field dependence from the Poole–Frenkel law are connected with the field-dependence of the Marcus transfer rates, transverse field dependences are related to the local structure of the material, namely local orientation of the chain segments with respect to the electrodes. Obtained results predict qualitatively different transverse field dependences for the gate fields oriented either parallel or perpendicular to the local chain segment alignment. We believe these findings can be useful for macroscopic simulations of electrical characteristics of the OFETs and other electronic devices based on conjugated polymers. It is particularly important for analyses of these characteristics aimed to better understanding phenomena influencing the charge transport near the organic semiconductor–insulator boundaries, which are very important for the optimal and stable performance of organic electronic devices.

References [1] P. Toman, M. Menšík, W. Bartkowiak, J. Pfleger, Physical Chemistry Chemical Physics 19 (2017) 7760. [2] P. Toman, M. Menšík, J. Pfleger, Chemical Papers (2018), https://doi.org/10.1007/s11696-018-0448-0.

Acknowledgement This work was supported by the Ministry of Education, Youth and Sports of the Czech Republic (Project COST LTC17029-

COST Action MP1406).

https://doi.org/10.1007/s11696-018-0448-0

103

Disposable Printed Ozone Dosimeter

Michal Veselý, Petr Dzik, Zuzana Petříčková

Brno University of Technology, Faculty of Chemistry, Purkynova 118, 612 00 Brno, Czech Republic,

[email protected]

Keywords: ozone, thin layer, printed dosimeter

Ozone is one of the gases that are naturally present in the atmosphere as a result of the interaction of sunlight with certain chemicals emitted into the environment. Ozone in air reduces odour problems, kill bacteria, fungi, mold and viruses. However, exposure to ozone is very harmful to human health, reduces agricultural crop yields, changes species composition in ecosystem and damages physical infrastructure and cultural heritage. Therefore, ozone represents a problem when its concentration in the atmosphere exceeds a certain threshold level.

There are many methods available for measuring atmospheric ozone concentrations; these are based either on ozone’s physical properties or on its consi-derable chemical reactivity. The monitoring of ground-based ozone is normally done by using spectroscopic methods. Ozone absorbs strongly in the ultraviolet and fortuitously the absorption maximum is located close to the principal emission line (254 nm) of a low pressure Hg-lamp. Most commercial ozone analyzers thus rely on measuring optical absorption at 254 nm over an extended path length.

While these techniques have been found to be stable and reliable, their applicability is somewhat limited by the fact that the instruments are usually expensive. There is now increased interest in alternative cheaper and disposable ozone dose indication paper.

In this work we prepared inks with several azo-dyes in organic solvent and polymeric compounds. These inks were coated on polyethylene terephthalate foil using Mayer rod and Baker film applicator technique. Coated samples with different dye concentration and layer pH value were exposed to ozone in ozone reaction chamber. Ozone was prepared in ozone generator from the compressed dry air at approximately 1 L.min

–1 flow rate.

The ozone concentration in the ozonized air was measured using UV spectrometer at 254 nm in 10 cm quartz cuvette. Before and after exposure, the reflec-tance spectra of all samples were measured by Spectrophotometer X-Rite Eye One Pro. Samples of printed samples were exposed to ozonized air to total bleaching in regular intervals.

Based on obtained results on disposable thin layer ozone dosimeters the new formulation of printing ink for screen printing technique was prepared. Thin layer ozone dosimeters based on azo-dyes cover ozone dose up to 120 mg.hour.m

–3 or 100 ppm (w) respectively. This ozone

dosimeters change their colours from orange to white, from deep violet to pale blue or from deep green to pale turquoise.

Acknowledgement Authors thank to Ministry of Education, Youth and Sports of the Czech Republic for support by project LTC17081.

104

Contact resistance effects in organic field-effect transistors

Martin Weis

Institute of Electronics and Photonics, Slovak University of Technology, Ilkovicova 3, 81219 Bratislava,

Slovakia

The organic field-effect transistors (OFETs) have been envisioned for future application because of many unique features such large-area and low-cost manufacturing, mechanical flexibility, biocompatibility, or optical transparency. Although the charge mobility of organic semiconductors is significantly lower than the one of inorganic materials, recent progress meets requirement of specific applications. However, improvement of the mobility revealed bottleneck in the charge injection in OFET devices. The energy barrier on the interface between metal electrode and organic semiconductor represents the contact resistance, which is a serious problem for practical applications of OFET. The contact resistance has many origins, such as the nonuniformity of organic semiconductors, the presence of dipole layers at the interface, electrode resistance, and the interfacial energy states. As a result, the contact resistance is not a single value as known in common inorganic semiconductors, but it is voltage dependent parameter.

We developed an electric-field enhanced thermionic emission model combined with an equivalent circuit for a three-terminal organic transistor structure to interpret

the gate-voltage dependent contact resistance. In the model the contact resistance is composed of two components: (i) the interfacial resistance not only influenced by interfacial energy barrier but also strongly dependent on active layer thickness, and (ii) the bulk resistance that is affected only by active layer itself. The model having physical meaning in the fitting parameters, different from the previous with simple power functions, can well fit the voltage dependence for a series of independent data. The developed model is helpful for understanding of contact resistance and charge carrier injection behavior in the organic thin film transistors.

Here we present the contact resistance study done on OFET device with pentacene as an organic semiconductors and various metals for source/drain contacts. It will be presented that the energy barrier height on the interface plays a crucial role in the contact resistance level. In addition, various parameters influencing the contact resistance will be discussed such as contacts architecture (the differences between the top, bottom, or immersed contacts), surface treatment and influence of ambient atmosphere, etc.

105

Artificial Photosynthesis: Learning from Nature

Dong Ryeol Whang

Linz Institute of Organic Solar Cells (LIOS) / Institute of Physical Chemistry, Johannes Kepler University

Linz, Altenberger Straße 69, 4040 Linz, Austria

Keywords: Artificial Photosynthesis, Photocatalysis, Electrocatalysis, Solar Fuel

Artificial photosynthesis has been devised and investigated in pursuit of solving 21st century’s energy problem. Despite such advances in recent decades, applying the technology in real life is still a challenging subject for the scientists. As the term “artificial photosynthesis” stems from mimicking the natural photosynthesis, we can learn from the nature’s strategies which have been evolved for 3.4 billion years. This talk highlights our recent progress on developing highly efficient and robust artificial photosynthetic systems by

mimicking the important strategies of natural photosynthesis.[1] Starting with a brief description of photosystem II in natural photosynthetic autotrophs, two relevant bioinspired strategies are discussed in this talk: i) accumulative charge transfer and ii) self-healing. Finally, remaining challenges and perspectives for future development of artificial photosynthesis will be discussed.

References [1] D. R. Whang, D. H. Apaydin, ChemPhotoChem 2 (2018) 148.

Acknowledgement This work was supported by the Austrian Science Foundation (FWF) within the Wittgenstein Prize of Prof. N. S. Sariciftci

(Z222-N19).

106

Organic field effect transistors based on hydrogen-bonded

semiconductor pigments

Cigdem Yumusak

Linz Institute of Organic Solar Cells (LIOS) / Institute of Physical Chemistry, Johannes Kepler University

Linz, Altenberger Straße 69, 4040 Linz, Austria

Keywords: Hydrogen-bonded pigments, Organic Field Effect Transistor, Bioelectronic applications

Hydrogen-bonded organic pigments are a class of materials familiar from applications in the colorant industry, where they find widespread use as materials for robust outdoor paints, cosmetics, and printing inks.

Indigo, a natural product, is the oldest and still most widely produced organic dye and pigment. The intermolecular hydrogen bonding that characterizes indigo is exploited in most of the synthetic hydrogen-bonded pigments as well. This class of materials has proven to be nontoxic and safe for humans, and is considered safer than even several classes of food dyes.

Hydrogen-bonding in general as a supramolecular engineering tool is useful to control self-assembly and highly relevant to aqueous and biochemical systems. Recently, we have found that indigo and some of its derivatives demonstrate ambipolar transport in organic field effect transistors, with mobility ranging from 0.01–0.4 cm

2 V

–1 s

1. We then reported on quinacridone, a

common industrial colorant perhaps best known as constituting the magenta printer pigment, as an ambipolar semiconductor with mobility in the 0.01–0.1 cm

2 V

–1 s

–1 range. Quinacridone also demonstrated the

formation of low-energy luminescent species, attributed to charge transfer excitons, which led to a low effective exciton binding energy and promising photovoltaic behavior. Alongside quinacridone, we evaluated its 4-ring analog epindolidione. Epindolidione demonstrated promising behavior in OFETs, providing hole mobility as high as 1.5 cm

2 V

–1 s

–1 with excellent stability in air and in

aqueous medium. Indigo, epindolidione, and quinacridone are all examples of hydrogen-bonded pigments where interplay between intermolecular H-

bonds and π–π stacking interactions lead to strong intermolecular interactions and high crystal lattice energy solids.

On the other hand, soluble organic semiconducting materials have a particular application potential for easily processed low-cost organic electronics devices. Solubility of organic π-conjugated small molecule derivatives, such as diketopyrrolopyrroles (DPPs), indigos, epindolidiones, squaraines and many other, is usually attained by a side-chain alkyl substitution, which is meant to interrupt inter- and intramolecular H-bonds. However, due to these bonds soluble organic semiconducting materials are usually less stable; moreover, as a result of tight aggregation of π-conjugated cores through intermolecular H-bond insoluble materials have shown high charge carrier mobilities for both electrons and holes. On the other hand, insolubility brings its obverse case: such materials are difficult to purify and they can’t be deposited by coating or printing techniques, which is a promising way towards cheap production of organic electronics.

In this report, we present a strategy to synthesize thermally stable and soluble high-performing DPP-based organic semiconductor for a wide range of electronics applications. The crucial component of the present approach is using adamantyl substitutions in solubilization side-groups. Due to its specific rigid, but strain-free structure adamantane forms a face-centered cubic lattice, which is unusual for organic compounds. This approach can be universally applied for many types of semiconducting organic materials, where solubilization is achieved by the side group substitution.

References [1] M. Irimia-Vladu, et. al., Adv. Mater. 24 (2012) 375. [2] E. D. Glowacki, et. al., Appl. Phys. Lett. 101 (2012) 023305. [3] E. D. Glowacki, et. al., J. of Mat. Chem. B 1 (2013) 3742. [4] E. D. Glowacki, et. al., Organic Electronics 15 (2014) 3521. [5] E. D. Glowacki, et. al., Adv. Funct. Mat. 25 (2015) 776. [6] A. Kovalenko, et. al., J. of Mat. Chem. C 5 (2017) 4716.

Acknowledgement This work was supported by the Austrian Science Foundation (FWF) within the Wittgenstein Prize of Prof. N. S. Sariciftci

(Z222-N19).

107

Inorganic Materials

108

Hybrid binder from recycled concrete powder and BPCKD

Bílek, V.

ZPSV.a.s.

Hybrid binders are based on ordinary portland clinker or cement, mineral admixtures as fly as or ground granulated blast furnace slag and alkali activator. Results for hybrid binders composed from ordinary portland cement, GBFS and bypass cement dust are compared with that for binders where OPC was replaced with concrete powder. Recycled concrete powder was

obtained from high performance concrete from concrete sleepers. This concrete contains big portion of unhydrated cement grains which can substitute portland cement or clinker. Water glass was used as an activator. Bypass cement dust (BPCD) contain high content of alkalies and it helps to activate slag.

109

Preparation and characterization of electroless Ni-P coating on

wrought ZE10 magnesium alloy

Martin Buchtík1, Petr Kosár1, Jakub Tkacz1, Pavel Doležal1,2, Jaromír Wasserbauer1

1 Brno University of Technology, Faculty of Chemistry, Purkyňova 464/118, 602 00 Brno, Czech

Republic

2 Brno University of Technology, Faculty of Mechanical Engineering, Technická 2896/2, 602 00 Brno,

Czech Republic

Keywords: Electroless deposition, Ni-P coating, magnesium alloy, ZE10, EDS analysis, microhardness,

adhesion, corrosion

Magnesium alloys are ranked among the lightest constructional metallic materials [1,2]. They find its application in automotive and aerospace industry due to their low density and high value of specific strength, toughness and good machinability [3]. Low corrosion resistance, high chemical reactivity, low hardness and low wear and abrasion resistance are considerable disadvantages of magnesium-based materials [4].

Mg-Zn-RE based magnesium alloys such as ZE10 and ZE41 achieve higher values of strength, and better mechanical and corrosion properties in comparison with the pure magnesium. These alloys contain beside Mg also Zn, rare earth (RE) elements – Pr, Nd, La, Ce, and a small amount of Zr. Although, these alloys achieve better mechanical and corrosion properties in comparison with pure magnesium, their surface properties such as hardness, corrosion and wear resistance are still inadequate for some industrial applications.

There exist several ways how to improve magnesium alloys surface properties and resistivity such as galvanic or electroless deposited coatings, thermally sprayed coatings or application of conversion coatings [5]. One of the ways suitable to protect the material to corrosion, including the improvement of the material surface mechanical properties, is the application of electroless Ni-P coatings in the electroless nickel bath [6]. Electroless deposited Ni-P coatings increase besides the corrosion resistance also the surface mechanical properties such as hardness and wear resistance. Applied low phosphorus Ni-P coatings are characteristic with a high value of hardness, high density, and crystallinity when compared to high phosphorus Ni-P coatings.

Deposited electroless low-phosphorus Ni–P coatings

were prepared on a surface of wrought ZE10 magnesium alloy in this work. An advanced pre-treatment of the substrate surface before the deposition included alkaline degreasing and acid etching. Uniform and homogeneous Ni–P coating with an average thickness of 10 µm was formed by 95.6 wt % Ni and 4.4 wt % P. The average

content of Ni and P was homogeneous in the entire cross-section of the deposited coating. Applying the Ni–P coating to the magnesium substrate, the surface microhardness increased from 60 ± 4 HV 0.025 to 690 ± 30 HV 0.025. Using the scratch test, it was determined that deposited Ni–P coating exhibits a high degree of adhesion to the ZE10 magnesium substrate. Electrochemical corrosion properties of ZE10 magnesium alloy and Ni–P coating deposited on ZE10 magnesium alloy were analyzed using the polarization tests in 0.1 M NaCl, while the deposited Ni–P coating showed the significant improvement of the corrosion resistance when compared to the ZE10 magnesium alloy. Using the scanning electron microscopy analysis, it was determined that the fine morphology of the deposited Ni–P coating did not contain visible microcavities and micropores. The absence of macrodefects due to the adequate pre-treatment before coating was reflected on the mechanism of the coated ZE10 degradation in a 0.1 M NaCl solution.

Figure 1: Fine morphology of deposited Ni-P coating

110

References [1] Friedrich, H. Mordike (eds) Springer Berlin 2004.

[2] ASM International Handbook Committee. Properties and selection: Nonferrous alloys and

special-purpose materials ASM International (10th ed) Materials Park.

[3] Miao, X.; Li, X.; Hu, H.; Gao, G.; Zhang, S. Coatings 8 (2018) 69-. [4] Shao, Z.; Cai, Z.; Hu, R.; Wei, S. Surface and Coatings Technology 249 (2014) 42-47. [5] Fauchais, P. L.; Heberlein, J. V. R.; Boulos, M. I. Springer New York 2013.

[6] Riedel, W. ASM International: Metals Park (Reprinted) Ohio, 1991.

Acknowledgement This work was supported by project Nr. LO1211, Materials Research Centreat FCH BUT- Sustainability and Development

(National Programme for Sustainability I, Ministry of Education, Youth and Sports).

111

Use of infrared spectroscopy as a tool for the identification and

analysis of inorganic materials

Jan Hajzler, Tomáš Opravil, Petr Ptáček, Petr Sedláček

Brno University of Technology, Faculty of chemistry, Institute of Materials Chemistry,

[email protected]

Keywords: infrared spectroscopy, KBr tablets, ATR crystal

The paper presents the possibilities of the effective use of infrared spectroscopy as a convenient tool for material identification. Spectra were collected on the selected inorganic samples, which are mostly based on silicon dioxide structure. The main goal is to study the effectiveness, quality and results of two different measuring techniques of the IR spectra collection. The

two typical techniques were applied, the transmission one being carried out with the use of KBr in form of tablets and the reflection one using the diamond ATR crystal. The spectra were collected in the middle infrared and far infrared region. From the collected data the influence of the selected measuring technique on the final results was discussed.

112

Durability of basalt fibres under the alkaline conditions

Hrubý, P., Kalina, L., Másilko, J., Pořízka J.

Brno University of Technology, Faculty of Chemistry, Purkyňova 118, 612 00 Brno, Czech Republic

Basalt fibres (BF) represent applicable reinforcement for the composite materials based on the alkali activated blast furnace slag (AABFS). Especially due to their favourable mechanical and thermal properties and chemical resistance. The AABFS represents a highly alkaline corrosive environment, therefore the durability of the BFs under these conditions is necessary to study before their implementation into these materials. The accelerated leaching tests of the BFs in various solutions were done for this purpose. The influence of the BFs

immersion to their durability was evaluated with a meaning of the loss of mass same as loss of tensile strength tests. The chemical composition changes of immersion solutions were characterized using the Inductively coupled plasma optical atomic emission spectroscopy (ICP-OES), meanwhile the changes of fibres themselves were determined using the X-ray Photoelectron Spectroscopy (XPS) and X-ray Diffraction analysis (XRD).

113

Alkali-activated slag-based systems with cement bypass dust

incorporation

Lukáš Kalina, Vlastimil Bílek Jr., František Šoukal, Tomáš Opravil

Brno University of Technology, Faculty of Chemistry, Materials Research Centre, Purkyňova 118,


Keywords: Alkali-activated slag, cement by-pass dust, shrinkage, expansion, setting time, strength

Cement bypass dust (CBPD) is a byproduct from clinker manufacturing process. Its composition and properties prevent its wide utilization in most applications. This study investigates its effect on alkali-activated slag (AAS) pastes and mortars properties, e.g. setting time, strength development, dimensional changes etc. The results showed that the action of CBPD

depends particularly on its dose as well as on the dose of alkaline activator. At low activator doses, increasing CBPD dose increases mechanical strengths of AAS, while opposite effect was observed at high activator doses. CBPD also accelerates AAS setting time significantly and can counteract its autogenous shrinkage.

114

Application of the theoretical knowledge of material engineering to

building practice

Konarik, J.

VŠB - Technical University of Ostrava

The paper is devoted to application of the theoretical knowledge of material engineering into building practice through the transfer of knowledge. Businesses do not have access to newly acquired research knowledge without active communication with research organizations, so they can not implement the latest knowledge in their production processes, use them to innovate their products and thus improve their market position. This state of affairs, ie the use of

outdated and overcome procedures, in the long run, causes the production of products which, by their quality, do not meet the expectations of customers and lead to a loss of competitiveness on the relevant market. The transfer of knowledge addresses the issue of improving the surface quality and extending the life of prefabricates using new knowledge from the research sphere and by improving the production processes in the company.

115

Anhydrite stabilization in refractory materials

Kotrla Jan, Ing., Šoukal František, doc., Ph.D., Švec Jiří, Ing., Ph.D.,

Brno University of Technology, Faculty of chemistry, Institute of Materials Chemistry,

[email protected]

Keywords: Fluid fly ash, refractories, water glass, anhydrite

The fluidized-bed combustion (FBC) fly ash in contrast with conventional fly ash contains less amorphous phase and more amounts of free lime and anhydrite. These differences make FBC fly ash impossible to use in the construction industry due to the low reactivity of the crystalline phase and volumetric changes connected with free lime hydration. On the other hand, the presence of anhydrite prevents usage in refractory materials, because at higher temperatures decomposition of anhydrite and release of sulfur dioxide

into the air take place. This study investigates the possibility of anhydrite stabilization at higher temperatures with sodium ions to form more stable compounds and the effect of the addition of sodium water glass to the resulting properties of refractory materials. XRD analysis and TG-DTA method were used to observe the newly formed compounds. The properties of the prepared samples were tested by heating microscope.

116

Resistance of cementitious composites against ballistic loading

Koutný Ondřej, Kratochvíl Jiří, Krátký Josef

Brno University of Technology

Presented study deals with the protective efficiency of cementitious composites to defeat the ballistic thread such as penetration of small arms armour piercing projectile. The ballistic performances of cementitious composites were monitored by samples of compressive strength from 20 MPa to 200 MPa via Depth of Penetration test using 7.62mm x 54R API B32

ammunition. The determination of ballistic efficiency residual velocity of projectile after perforation the sample with constant thickness i.e. the residual penetration depth into the witness system. These parameters are used for determination of general material characterization of protective capabilities against ballistic threat.

117

Basics of ballistic protection design

Jiří Kratochvíl, Ondřej Koutný, Jiří Švec, Josef Krátký

Tomas Bata University in Zlín, Faculty of technology

This study describes steps leading toward successful design of armor system against specific ballistic threat. First is the weight limitations. Next step includes theoretical design and armor composition based on numerical simulations in order to fulfil weight limitations set in the first step. After first ballistic tests, numerical model is refined and adjusted. For this initial testing and

numerical model adjustment most suitable are depth of penetration test and ballistic limit test. These tests are suitable mostly for testing individual components of the armor system and preliminary designs. After final armor plate design, sample is manufactured and tested according to STANAG 4569.

118

Ash – the raw material base for the future

Marko M., Opravil, T., Šoukal F., Pořízka J.

Brno University of Technology, Faculty of Chemistry, Purkyňova 118, 612 00 Brno, Czech Republic

Keywords: Secondary raw materials, raw material base, fly ash, fly ash utilization, recovery of

alumina from fly ash.

This paper responds to the worldwide problem concerning in the search of new material base for the future usage. Solid residues from high temperature or fluid coal combustion could be one of many alternatives to the raw materials. The study deals with the analysis of side energy products produced by power plant industry in the Czech Republic.

Based on the ash chemical composition, possibilities of aluminium and even iron and titanium separation were proposed and then proved in the laboratory scale.

Extracted components were separated selectively using apropriate methods. Then a couple of sintering reactions leading to improvement the leachability of selected elements from the fly ash matrix were carried out.

Appropriate input material modification by high-temperature sintering reaction with calcium chloride and calcium carbonate combined with extraction process in the sulfuric acid solution leads in dissolution up to 99 % of aluminium from the fluid and high-temperature fly ash.

119

Development of heavyweight concrete for an eventual gamma and

neutron-rays shielding application

Janette Dragomirová, Martin Palou

Institute of Construction and Architecture, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 03

Bratislava, Slovak Republic, [email protected]

Keywords: Heavyweight concrete, barite, magnetite, mechanical properties, irradiation

Two types of heavy aggregates (barite and magnetite) and their mix were used to manufacture three heavyweight concretes using CEM I 42,5 R and blend cement comprising metakaolin, silica fume and blast furnace slag with replacement level of 25 wt. %. Slump test, compressive strength, elastic modulus, freeze-thaw resistance, weight density of fresh and hardened concrete samples were determined. The weight density varied from 3200 kg m

-3 for barite

concrete to 3700 kg m-3

for magnetite concrete. The test of compressive up to 28 days has demonstrated that the samples belong to the class of high-compressive strength concrete with values exceeding 70 MPa. Comparing the laboratory results of physical and mechanical properties reported in different references, the present samples are considered as high-performance heavyweight concretes with possibility to be used as biological shielding in nuclear plants.

The manufacture of optimized heavyweight concrete takes into consideration the type of aggregates, composition of blended cement, water-to-cement ratio, additives etc. The density of concrete depends mainly on the specific gravity of the used aggregates. Generally, concrete with specific gravities higher that 2600 kg m

-3

are called heavyweight concrete and aggregate with specific gravity higher than 3000 kg m

-3 are considered

as heavyweight aggregate according to EN [1]. Concrete is easy to produce in varied compositions. It is composed of a well-proportioned mixture of light and heavy nuclei. It is therefore efficient both in absorbing gamma rays and in slowing down fast neutrons by elastic and inelastic scattering [2]. Light materials, especially hydrogenous materials which contained in the water of

hydration of the set cement (concrete) attenuate fast neutrons as a consequence of the high cross-section of hydrogen [3].

In the case of application of concrete structures in irradiated environment, the chemical composition of individual constituents is even more decisive as it affects the shielding capacity with possible attenuation performance, volumetric stability and other mechanical properties [2]. The heavy aggregates containing many heavy elements are crucial in improving concrete shielding properties and hence contribute greatly to the attenuation of photons and neutrons. It is a general concept, but based on experimental data that the compressive strength of concrete exposed to strong neutron and gamma-ray radiation decreases with an increase in the neutron radiation fluency, also with exposition time. The main explanation is mainly associated with the volume expansion of aggregates. Concrete being a composite materials, the chemical composition of each constituents plays a key role in its structure integrity (durability and service-ability), also during the long-term exposition to nuclear irradiations. The irradiation temperature can exceed 400 °C. Moreover the temperature of pressurized water reactor in some part of steam turbine can also exceed 380°C. At these temperatures, some hydration products, namely calcium silicate hydrates and ettringite are degraded causing the depletion of pore structure, and consequently by the decreases of structure integrity.

The present work is undertaken to develop heavyweight concrete with supplementary cementitious materials and two kinds of high density concrete and their mix for possible testing of radiation shield.

Acknowledgements This work was supported by courtesy of APVV-15-0631 and V4-Korea Joint Research Program- Radcon.

References [1] STN EN 206-1. Concrete_Part 1: Specification, Performances, Production and Conformity STN. Bratislava; 2002. [2] Kyoungsoo P. Hyung_tae K., Tae-Hyun K., Eunso Ch. Effect of neutron irradiation on response of reinforced concrete members for nuclear power plants. Nuclear Engineering and Design 310 (2016) 15-26 [3] Ahmed S. Ouda. Development of high-performance heavy density concrete using different aggregates for gamma-ray shielding. Housing and Building Reasearch Center HBRC Journal,(2015) 11, 328-336.

120

Formation of clinker containing lithium

Theodor Staněk1, Alexandra Rybová2, Anežka Zezulová3, Martin Boháč4

1 Research Institute for Building Materials, Hněvkovského 30/65, 617 00 Brno, Czech Republic,

[email protected] 2 Research Institute for Building Materials 3 Research Institute for Building Materials 4 Research Institute for Building Materials

Keywords: clinker formation, phase composition, alite, lithium

Lithium consumption in the production of batteries and accumulators for energy storage is increasing. It can be foreseen that the amount of waste with higher content of this metal will grow. Cement industry is one of the major consumers of several types of waste and secondary raw materials, therefore it is desirable to study the impact of lithium on the properties of clinker and cement.

Lithium behaves differently from sodium and potassium. It forms non-volatile Li2O at higher temperatures and mainly it decreases the temperature of melt formation [1].

Presence of Li2CO3 decreases decomposition temperature of CaCO3, whilst the process happens in two steps [2].

Kolovos et al [3] studied influence of addition of 2.5 wt. % Li2O on the structure of clinker burned at 1450 °C.

Under laboratory conditions, it has been found that lithium has a significant impact on clinker melt formation and on the formation of alite - the main clinker phase. Following experiment study the influence of Li2O addition (in form of Li2CO3) in the amount from 0.5 to 5 wt. % on phase composition and clinker structure. The research was conducted by means of XRD, DTA and optical and electron microscopy. The research deepens the current knowledge about the effect of these oxides on phase composition and structure of clinker and on polymorphism of clinker phases.

It was found that increasing content of Li2O lowers CaCO3 decomposition temperature and also clinker melt is formed at lower temperature comparing to clinker without any addition (the difference is more than 100 °C). Alite is formed already at 1200 °C and its crystals are observably bigger (see fig. 1 and 2) – due to significantly lower viscosity of clinker melt.

Figure 1: Alite crystals in the clinker without Li2O

Figure 2: Alite crystals in the clinker with 4 wt. % Li2O

Moreover, it was found that increased amount of Li2O can cause alite decomposition into microcrystalic mixture of belite and free lime. Lithium stabilizes monoclinic alite modification, β belite modification and cubic C3A.

References [1] Role of Minor Elements in Cement: Manufacture and Use. Javed I. Bhatty (Ed.), PC Association, Skokie, 1995. [2] P. Saraswat, V.K. Mathur, S.C. Ahluwalia, Termochimica Acta 97 (1986) 313-320. [3] K. Kolovos, S. Tsivilis, G. Kakali, Cement and Concrete Composites 27 (2005) 163-170.

Acknowledgement This research was done within the project No. 16-08959J financed by the Czech Science Foundation.

121

Differences in use of isothermal and isoperibolic calorimetry to

assess the effect of zinc on hydration of cement blended with

ground blast furnace slag and silica fume

Pavel Šiler1, Iva Kolářová1, Jiří Dobiáš1, Radoslav Novotný1, Jiří Másilko1, Jiří Švec1, Jan Bednárek1,

Martin Janča1, Tomáš Opravil1


The amount of zinc in the clinker or in the secondary raw materials is increasing in recent years thanks to using of zinc solid waste or tires in Portland cement manufacturing. Zinc may be present also in the primary secondary raw materials, where the manufacturing process leads to its removal and concentrating to "waste" which is used in the cement industry.

The aim of this work was to determine the effect of zinc on the hydration of Portland cement doped with ground blast furnace slag (GBFS) and silica fume (SF). This effect was studied by isothermal and isoperibolic calorimetry in case of GBFS. An effect of SF was studied

only by isoperibolic calorimetry, but different cements (42.5 R and 52.5 N) and different cement to binder ratio (0.3, 0.325, 0.35 and 0.4) were tested. Isoperibolic calorimetry monitors hydration process in real conditions, while isothermal calorimetry in defined chosen temperature. Zinc for study of combined effect with GBFS was added to the cement in the form of two-soluble salts of Zn(NO3)2, ZnCl2 and a poorly soluble compound ZnO. In case of SF only ZnO influence was tested. The concentration of zinc added was chosen as 0.05, 0.1, 0.5, and 1wt%.

122

Portland clinker characterization by scanning electron microscopy

with BSE, EDS, WDS and EBSD

Šoukal, F.1, Opravil, T.1, Ptáček P.1, Staněk T.2

1 Brno University of Technology, Faculty of Chemistry, Purkyňova 118, 612 00 Brno, Czech Republic 2 Research Institut of Building Materials, Hněvkovského 65, 617 00 Brno, Czech Republic

The composition and the structure of Portland cement clinker is used to characterized by a number of common techniques such as XRF, XRD, optical microscopy that are applied in clinker production quality control. Further research of Portland clinker utilizes other additional analytical techniques to study its chemical and phase composition and microstructure. The paper shows the possibilities of Portland clinker characterization by scanning electron microscope utilizing detector of backscattered electrons (BSE), energy-dispersive spectrometry of characteristic X-rays (EDS), wave-dispersive spectrometry of characteristic X-rays (WDS) and electron backscatter diffraction (EBSD). Based on atomic number the BSE enables to distinguish

the individual phases of Portland clinker including detailed microstructure of aluminate and ferrite phases even at highest magnification. Information regarding the distribution of elements in a clinker can be very easily acquired by elemental EDS mapping. WDS thanks to its better detection limits and spectral resolution can be used for quantification of elements (e.g. Na, K, S, Mg, Fe, Cl) within the clinker phases in solid solutions. And finally EBSD is very advanced method for identification of minerals in clinker including their crystallite size, shape and orientation. On the other hand EBSD measurement requires difficult sample preparation and treatment. A novel method of nonconductive sample (clinker) preparation for EBSD is also presented.

123

Porous hydroxyapatite/alumina composites intended for bone

tissue engineering

Jan Vojtisek, Eva Bartonickova, Juliana Drabikova, Jaromir Porizka


This work deals issues of ceramics materials suitable for tissue engineering. An artificial substitute for human tissue can be divided to several generations. This include inert, bioactive and bioresobable materials. Resorbable substitutions are prepared from materials, which could substitute host tissue, for example hydroxyapatite. HA can be prepared in different ways (dry and wet way). To better application in medicine, ceramics foams prepared by in situ foaming or replication technique are using. Experimental part of this paper deals preparing of

hydroxyapatite powder and process optimization. Samples was characterized by IR and Raman spectrometry, XRD analysis and particle size was studied by SEM. Ceramics foams was prepared by in situ foaming from Al2O3, HA and composites (in ratio 50 - 50, 75 - 25, 90 - 10). Porosity was evaluated by stereomicroscope, density and level of sintering was studied by SEM microscopy. Porous scaffolds were studied by means of basic apatite ability testing.

124

Functional Materials

125

Processing stabilization of poly(3-hydroxybutyrate)/poly(lactic acid)

blends with oligomeric carbodiimide

Veronika Melcova1, Radek Prikryl1, Premysl Mencik1, Jiri Tochacek2

1 Materials Research Centre, Faculty of Chemistry, Brno University of Technology

Purkynova 464/118, CZ-612 00 Brno, [email protected] 2 CEITEC, Brno University of Technology, Purkynova 123, CZ-612 00 Brno

Keywords: poly(3-hydroxybutyrate), poly(lactic acid), carbodiimide, stabilization, reactive extrusion

Poly(3-hydroxybutyrate) (PHB) and poly(lactic acid) (PLA) are both bio-polyesters, frequently blended to overcome each other’s drawbacks. Their compatibility can be accomplished by partial cross-linking with dicumyl peroxide [1]. However, radical reactions lead to hardly identifiable structures and even to gel formation. Therefore, it is to find non-radical compatibilizing and stabilizing reagents. As for PLA, there are articles describing the use of tris(nonylphenyl) phosphite (TNPP), multi-functional epoxide styrene-acrylic oligomeric chain extenders (Joncryl) and oligomeric carbodiimide [2], pyromellitic dianhydride with triglycidyl isocyanurate [3] or triphenyl phosphite (TPP) [4]. None of these has been studied with PHB and PHB/PLA blends with PHB majority though.

In this work, firstly the reactivity of different reactive agents in amount of 2 % towards neat PHB and PLA was studied. Five following additives were selected - Joncryl, oligomeric carbodiimide with commercial name Raschig 9000, TPP, TNPP and diphenyl isodecyl phosphite. Analogous to [1], melt reactions were carried out in laboratory kneader with simultaneous recording of the melt torque in time. Among the tested compounds, only Raschig was proven to enhance melt torque of both polymers.

In order to find the most efficient amount of Raschig for stabilizing of both polymers and PHB/PLA (70/30 w/w) blend, experiments with different amounts of Raschig were performed. In Figure 1, there is differential torque plotted against time after feeding for samples of PHB/PLA blend with 0, 0.5, 1, 2 and 3 % of Raschig. Differential torque was obtained by subtracting the values of neat polymer in order to better evaluate the contribution of the additive.

Figure 1: Time dependency of differential torque for PHB/PLA samples with different concentrations of Raschig

The influence of the amount of Raschig addition was further studied by means of rheology and gel permeation chromatography (GPC). All results showed the same trend for neat polymers and their blend. The addition of more than 0.5 % wt. did not have any further positive effect on molecular weight or complex viscosity of the melt. Greater amount is not consumed during the reaction and is left in the sample leading to the decrease in number average molecular weight (MW) meanwhile weight average MW is increased (Table 1). Therefore, 0,5 % of Raschig was used for processing stability studies on PHB/PLA blends by subsequent extrusion cycles.

Table 1: GPC results of PHB/PLA samples with Raschig addition

PHB/PLA

Raschig amount (%) 0 0,5 1 2 3

Mn (kg·mol‒1) 89 86 78 69 53

Mw (kg·mol‒1) 231 253 248 250 242

References [1] W. Dong, P. Ma, S. Wange et al. Polymer Degradation and Stability 98 (2013), 1549-1555. [2] N. Najafi, M.C. Heuzey, P.J. Carreau. Polymer Engineering and Science 53 (2013), 1053-1064. [3] J. Liu, L. Lou, W. Yy et al. Polymer 51 (2010), 5186-5197. [4] J. Xie, R. Yang. Journal of Applied Polymer Science 124 (2012), 3963-3970.

Acknowledgement Materials Research Centre at FCH BUT-Sustainability and Development, REG LO1211, with financial support from the National Programme for Sustainability I (Ministry of Education, Youth and Sports).

-0.5

0.0

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nti

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orq

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·m)

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PHB/PLA 0%R PHB/PLA 0.5%R

PHB/PLA 1%R PHB/PLA 2%R

PHB/PLA 3%R

126

Biodegradable composite materials based on

poly(3-hydroxybutyrate) for 3D printing applications

Premysl Mencik1, Veronika Melcova1, Radek Prikryl1, Sona Kontarova1, Jano Bockaj2, Pavol Alexy2

1 Brno University of Technology, Faculty of Chemistry, Purkynova 464/118, 612 00 Brno,

[email protected] 2 Slovak University of Technology in Bratislava, Faculty of Chemical and Food Technology,

Radlinskeho 9, 812 37 Bratislava 1

Keywords: Poly(3-hydroxybutyrate), Kaolin, Limestone, Bio-composite, 3D print

Presented work deals with the development of bio-source and biodegradable composite material for 3D printing. Polymer blend based on PHB (60 w.%) and PLA (25 w.%) plasticized by tributyl citrate (15 w.%) was used as a matrix. This base blend was filled with 10 vol.% of kaolin or limestone. For the surface treatment of the limestone samples zinc stearate was used. The mechanical and thermal properties of the composites, as well as their behavior during 3D printing process, were compared with unfilled blend and commercial PLA 3D printing filament.

Warping behavior, one of the main problems of 3D printing materials, was studied by means of warp coefficient. This stands for the height of the V-shaped test warping specimen divided by maximum height reached during printing until the material starts to detach from the bed. The testing specimen is shown in figure 1 and comparison of the warping results is on the figure 2.

Figure 1: The V-shaped test warping specimen.

Cross-sections of specimens printed under the same temperature conditions were observed. In the case of composite samples, individual filaments were separated. This was caused by higher viscosity of composite samples

than that of polymer matrix. Despite the separation, kaolin and surface treated limestone filled composites exhibited satisfying mechanical properties.

SEM analysis confirmed good particle distribution of the samples with kaolin and surface treated limestone. No significant particle agglomerates were formed in the composites with limestone proving good dispergation ability of zinc stearate.

Figure 2: Warp coefficient of unfilled polymers and composite samples filled by kaolin and limestone.

TGA and DSC analysis showed no degradable effect of the used fillers on base polymer matrix.

Observed results indicate that kaolin and surface treated limestone are suitable fillers for the bio-source composites used for 3D printing.

Acknowledgement This work was supported by the Materials Research Centre is supported by the Ministry of Education, Czech Republic

(project No. LO1211).

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127

Adhesion and Mechanical Properties of a-CSi:H Thin Films Prepared

from Tetravinylsilane Monomer by Plasma Polymerization

Tomas Plichta1, Martin Branecky1, Vladimir Cech1

1 Brno University of Technology, Faculty of Chemistry, Institute of Materials Chemistry, Purkynova

464/118, 612 00 Brno, Czech Republic, [email protected]

Keywords: thin films, a-CSi:H, PECVD, nanoscratch test, adhesion, nanoindentation, mechanical

properties, atomic force microscopy

The adhesion of the thin film to the substrate and mechanical properties of this film are some of the most important and crucial attribute in determining the thin film's application possibilities. Thin films with controlled adhesion are essential as barrier, anti-scratch, wear-resistant, transparent and antireflective coatings for surface modified materials. The greatest potential of this research for industrial applications is in glass-fiber-reinforced polymer composites without sharp interfaces.

In this study, hydrogenated amorphous silicon-carbon (a-CSi:H) thin films were studied from the point of adhesion to the silicon substrate. Silicon wafers were pretreated with argon plasma (5.7 Pa, 10 sccm, 5 W, 10 min) using continuous wave to reach reproducible thin film adhesion. Thin films were deposited by plasma-enhanced chemical vapor deposition (PECVD) from pure tetravinylsilane (TVS) monomer (2.7 Pa, 3.8 sccm), employing a radiofrequency (RF) helical coupling system, using a pulsed regime with effective power ranging from 2 W to 150 W. Prepared films were 0.1 μm thick for nanoscratch testing and 1.0 μm for nanoindentation measurement.

The nanoscratch test consisted of drawing a conical diamond indenter (90°, 1 μm tip radius) over a film under linearly increasing normal loading from 1 μN up to 10 mN. The scratch length was 10 μm and was reached in 30 s. The value of the load at which adhesion failure is detected is known as the critical normal load (Lc), which is used as a semiquantitative measure of adhesion. Scratch tracks were also observed by atomic force microscopy (AFM) and correlated with loading curve (Fig. 1).

Young's modulus and hardness were obtained by instrumented nanoindentation technique using Berkovich indenter (50 nm tip radius). Analysis of load-displacement curves was based on Oliver-Pharr method.

It was observed that critical load increased with enhanced power from 1.6 mN (2 W) up to 4.6 mN (75 W) and was invariable for higher power 4.4 mN (150 W). The

measurements showed an increase in Young's modulus in dependence on effective power, specifically from 10 GPa (2 W) to 140 GPa (150 W).

Although critical load has been found to increase with enhanced power, work of adhesion is decreasing. This fact is due to the significant effect of Young's modulus, which grows vigorously, on the critical load value. Based on model Burnett and Rickerby [1] and modified by Bull et al. [2], the work of adhesion, eliminating the influence of variable Young's modulus, was used.

It was found out that the adhesion of the films for 4 years was without changes, it means with no aging effect.

Figure 1: Evaluation of the critical normal load as the measure of adhesion.

References [1] P. J. Burnett, D. S. Rickerby, Thin Solid Films 157 (1988) 233–254. [2] S. J. Bull, D. S. Rickerby, A. Matthews, A. Leyland, A. R. Pace, J. Valli, Surf. Coat. Technol. 36 (1988) 503–517.

Acknowledgement This work was supported in part by the Czech Science Foundation, grant no. 16-09161S and the BUT Specific Research,

grant no. FCH-S-18-5194.

128

Synthesis of lactic acid-based thermosetting bio-polyester

Tomáš Porubský1, Mikael Skrifvars2, Jaroslav Petrůj1

1 Department of material chemistry, Brno University of technology, Purkyňova 118, 612 00 Brno,

Czech Republic, [email protected] 2 University of Borås, Allégatan 1, S-501 90 Borås, Sweden

Keywords: renewable resources, lactic acid, itaconic acid, isosorbide, unsaturated polyester,

thermosetting resin, shape-memory

Currently, unsaturated polyester resins (UP) are composed of phthalic and maleic acid moieties connected by various diols, mainly ethylene and propylene glycol. Unsaturation for resin itself is provided by incorporation of the maleic anhydride only. UP’s often contain reactive diluent to adjust its viscosity, crucial parameter important for convenient processing of resin in composite manufacture. Polyester resins used for sheet molding compounds often contain styrene as reactive diluent, which can migrate from the resin or composite and act harmfully for the environment. New bio-source feedstocks now offer possibility to replace conventionally used fossil based chemicals completely or at least from major part. Nowadays, lactic acid, various sugar derived chemicals (isosorbide, starch, etc.), itaconic acid, unsaturated fatty acids and others are being used in research as potential renewable building blocks for polyester formation [1]. Use of lactic acid for production of thermoplastics is well known, but only a few studies are devoted to lactic acid based thermosets.

In scope of this work, novel linear UP’s was synthesized using isosorbide together with 1,2-propanediol as diol compounds, itaconic acid providing the unsaturated exo-vinylidene reactive double bonds and different amounts of lactic acid. Isosorbide was thought to give the resin higher stiffness and enhance thermal resistance and thus substitute the aromatic phthalic anhydride originating from fossil derived sources. Bis(2-hydroxyethyl)terephthalate obtained from waste PET scrap glycolysis was also used as alternative source of aromaticity. Itaconic acid, contrary to maleic acid, is more reactive and can be homopolymerized without the addition of any other reactive monomer. Lactic acid brings polar groups into the chain that can be advantageous in composite manufacture, while fiber treatment would not be necessary for better interfacial adhesion.

Prepolymer polyester was prepared by melt polycondensation catalyzed by methylenesulfonic acid to obtain product with acid number less than 50 mg KOH/g. Molecular weight of the polyester was determined by GPC to be around 2000 g·mol

–1. This polyester was

further reacted with allyl alcohol and formed hydroxyl end-groups were methacrylated subsequently. Non-cured

resins showed different viscosity dependent on the feed composition. Obtained resins spanned from viscous liquids to soft solids. Therefore, bio-based reactive diluent – dimethylitaconate (DMI) was used to dissolve the resin to get pourable polymer mixture. Effects of two reactive diluents, DMI and styrene, on resin properties were evaluated as can be seen in Table 1. Solubility of the biopolyesters in DMI and in styrene was modelled using Hansen solubility parameter. Thermally cured bio-UP resins were characterized by FTIR, TGA and DMA. Mechanical properties of the UP resins were measured as well. Results were compared with previous work [2], in which only simple glycols (propylene glycol, 1,4-butanediol) were used as hydroxyl donor. Prepared resins possess good thermomechanical properties (Figure 1) comparable to commercial UP resins and can be used in composite manufacture, for construction applications, coatings and adhesives. Some compositions, with DMI reactive diluent, showed interesting shape-memory effect.

Figure 5: Effect of the resin composition on tan δ and Tg

Table 1: Effect of reactive diluent on cured resin properties Sample E (MPa) σ (MPa) Tg (°C)

IA_PG12_PET20_LA30 3940 ± 380 69,1 ± 6,3 85,7

IA_PG12_PET20_LA30_DMI20 3220 ± 190 52,6 ± 0,1 69,4

IA_PG12_PET20_LA30_St20 3510 ± 330 50,9 ± 1,4 124,4

References [1] Handbook of thermoset plastics, A. Dotan, Boston: William Andrew Publishing, 2014, p. 577-622. [2] T. Porubský, M. Skirfvars, D. Åkesson, Career in Polymers IX, Book of Abstracts. Prague, Czechia, 2017, p. 61.

129

The Effect of Bioactive Additives on Morphology and Biological

Properties of Collagen-Based Nanostructured Resorbable Skin

Substitutes

Lucy Vojtova1,2, Johana Babrnakova1, Veronika Pavlinakova1, Lucie Vistejnova3, Veronika

Stepankova4, Eva Filova5, Martin Knoz6,7,8, Bretislav Lipovy6,7, Jakub Holoubek6, Zdenek Pavlovsky6,

Martin Faldyna9, Eduard Göpfert9, Jiri Damborsky10, Vanessa Hearnden11

1 CEITEC – Central European Institute of Technology, Brno University of Technology, Advanced

polymers and composites, Purkyňova 656/123, 612 00 Brno, Czech Republic 2 Brno University of Technology, Faculty of chemistry, Institute of Materials Science, Purkyňova

118, 612 00 Brno, Czech Republic 3 Biomedical Center, Faculty of Medicine in Pilsen, Charles University, Czech Republic 4 Enantis s.r.o, Brno, Kamenice 771/34, 625 00 Brno, Czech Republic 5 Institute of Experimental Medicine, Academy of Science of the Czech Republic, Vídeňská 1083,

142 20 Prague, Czech Republic 6 Department of Burns and Plastic Surgery, University Hospital Brno, Jihlavská 20, 62500 Brno 7 Faculty of Medicine, Masaryk University, Kamenice 753/5, 625 00 Brno 8 Department of Plastic and Aesthetic Surgery, St. Ann‘s University Hospital, Pekařská 53, 656 91

Brno, Czech Republic 9 Veterinary Research Institute, Hudcova 296/70, 621 00 Brno, Czech Republic 10 Institute of Experimental Biology and Recetox, Kamenice 753/5, Masaryk University, Brno 11 Department of Materials Science and Engineering, University of Sheffield, UK

Keywords: 3D scaffolds, biocompatibility, angiogenesis, in vitro, skin defect

Advanced nanotechnology finds growing use in the field of clinical medicine. A vision of current clinical practice in the treatment of chronic skin defects as well as acute wounds (such as mechanical trauma or burn trauma) is controlled healing of the wound in the dermis of the missing skin. Controlled healing allows both controlled scar maturation and dramatic improvements in viscoelastic properties of newly created skin. The aim of the study was to prepare nanostructured porous skin replacements modified with biologically active polysaccharides and growth factors.

The resorbable dermal replacement was made up of two nanostructured biocompatible layers. The lower part (dermis substitution) was prepared from biopolymer porous foam modified with a highly stable fibroblast growth factor 2 (FGF2). The upper part (dermo - epidermal substitution) consisted of a layer of amphiphilic polymeric nanofibers ensuring optimal adhesion to the epidermal graft. The effect of FGF2 concentration on morphology and biological activity of the skin substitutes

was optimized in-vitro by colonization of 3T3 line of mouse fibroblasts. As confirmed by ex ovo Chick Chorioallantoic Membrane assay, stable FGF2 also significantly enhanced neovascularization efficiency of biopolymer substitutes. Regenerative ability of the resorbable bilayer implant enriched with FGF2 was evaluated in a full-skin thickness defect on both small and large animal model (New Zealand rabbit and Large white pig, respectively). Histological and immuno-histological analysis of samples taken on the 14th postoperative day from rabbit defects confirmed the resorption of the biopolymeric bilayer and wound healing in the entire defect with the positive effect of FGF2. In both rabbits and pigs, the bilayer skin replacements showed the formation of new connective tissue without immune cells infiltration. The tested 3D bilayer biomaterial has proven optimal properties for application to skin defects and wounds, shelf life under sterile conditions, resistance to infection, biocompatibility with proliferative and healing potential, and has the potential for the use in human medicine and clinical practice.

Acknowledgement This work was supported by the CEITEC 2020 (LQ1601) with financial support from the Ministry of Education, Youth and Sports of the Czech Republic under the National Sustainability Programme II and by the Ministry of Health under the project no. 17-29874A.

130

Young Researchers Forum

131

Cytotoxic activity of liposome particles with natural source of

antioxidants for food and cosmetic application

Jitka Bokrova1,2, Ivana Maslonkova2, Renata Pavelkova1,2, Petra Matouskova1,2, Ivana Marova1,2

1 Material Research Centre, Brno University of Technology, Faculty of Chemistry, Purkynova

464/118, 612 00 Brno, [email protected] 2 Brno University of Technology, Faculty of Chemistry, Department of Food Science and

Biotechnology, Purkynova 464/118, 612 00 Brno

Keywords: cytotoxicity, liposome particles, natural antioxidant

Recently, production of nanoparticle formulations in food, pharmaceutical and cosmetic industry has highly increased. Due to their wide application, human organisms are exposed to nanoparticles on a daily basis. Small size of nanoparticles (10 – 1000nm) provides them with many specific physicochemical characteristics and thereby nanoparticles has to be assessed for their possible harmful effects on human health [1,2].

Liposome particles are widely used in manufacturing because of their appropriate size, biocompatibility and biodegradability. Moreover, liposomes allow encapsulation of both hydrophilic and hydrophobic compounds and therefore protect actives against environment [3,4].

Antioxidants are common active ingredients in food and cosmetic formulations. They serve also as protectors of other components oxidation. Antioxidants have ability to terminate harmful chain reactions by inhibiting free radicals and thus, prevent oxidative damage of final products [5]. Very valuable source of complex antioxidants are plants. Phyto-antioxidants are most often phenolic compounds, their antioxidant properties are provided by many hydroxyl groups in the structure. Besides, chosen extracts of plant antioxidants can have anti-inflammatory and antimicrobial effects and thus represent a very useful tool for preserving stability of food and cosmetic products [6].

References [1] YANG, H., LIU, Ch., YANG, D., ZHANG, H., XI, Z. Comparative study of cytotoxicity, oxidative stress and genotoxicity

induced by four typical nanomaterials: the role of particle size, shape and composition. Journal of Applied Toxicology 29 (2009) p. 69-78.

[2] CLIFT, Martin J.D., Sourav BHATTACHARJEE, David M. BROWN a Vicki STONE. The effects of serum on the toxicity of manufactured nanoparticles. Toxicology Letters 198 (2010) p. 358-365.

[3] AKBARZADEH, Abolfazl, Rogaie REZAEI-SADABADY, Soodabeh DAVARAN, et al. Liposome: classification, preparation, and applications. Nanoscale Research Letters 8 (2013), p. 102.

[4] KNUDSEN, Kristina Bram, Helle NORTHEVED, Pramod KUMAR EK, et al. In vivo toxicity of cationic micelles and liposomes. Nanomedicine: Nanotechnology, Biology and Medicine 11 (2015) p. 467-477.

[5] KUSUMAWATI, I., INDRAYANTO, G. Natural Antioxidants in Cosmetics. Studies in Natural Products Chemistry 40 (2013), p. 485-505.

[6] FANG, Z., BHANDARI, B. Encapsulation of polyphenols – a review. Trends in Food Science & Technology 21 (2010) p. 510-523.

Acknowledgement

“Materials Research Centre - Sustainability and Development" Nr. LO1211, of the Ministry of Education, Youth and Sports.

http://www.sciencedirect.com/science/bookseries/15725995

132

High-ordered adamantane-substituted industrial organic dyes for

organic semiconducting materials

Martin Ciganek1, Jozef Krajcovic2

1 Brno University of Technology, Faculty of Chemistry, Materials Research Centre, Purkyňova 118,

612 00 Brno, Czech Republic, [email protected] 2 Brno University of Technology, Faculty of Chemistry, Materials Research Centre, Purkyňova 118,


Keywords: adamantane, diketopyrrolopyrrole, organic electronics, organic dyes, ambipolarity

The series of three derivatives of 2,5-dihydropyrrolo [4,3-c]pyrrolo-1,4-dione (DPP) modified by adamantyl-ethyl solubilisation side groups was prepared.

N

N

O

O

Ar

Ar

Ar: S

S

S

S

S

S

(1)

(2)

(3)

Figure 1: The series of three prepared DPP derivatives

The incorporation of adamantyl chains into DPP molecule induces π–π interactions between the conjugated DPP cores through adamantyl–adamantyl stacking, which causes extraordinary interesting arrangement of the molecules [1]. At basic thiophene-DPP with adamantyl-ethyl chains (1), it was observed the distance between the DPP cores only 3.37 Å and unusually planarity with torsion angle of the thienyl group against DPP core only 1.79°, which is the smallest value in

comparison with reported N,N’-alkylated derivatives with n-hexyl and 2-ethylhexyl chains [2].

This unique arrangement strongly amplifies charge transfer in the material and it is responsible for its ambipolar characteristic with excellent electron mobility of 0.2 cm

2 · V

–1 · s

–1 [1], which is unprecedented value for

such modified derivatives [3]. The significant advantage for purification and

processing of the derivative is the fact that the material is soluble in most common organic solvents after a modification by incorporation of adamantyl chains. Other huge benefit of this approach is a possibility to apply it for varied scale of high-performance organic pigments, containing the lactam motive, which are able to be modified by side-group substitution.

In other part of the work, the prolongation of π-conjugation of the above-mentioned DPP derivative was studied. The π-conjugation was extended by 1 and 2 thiophene units from each side at positions 3 and 6 of the DPP molecule. The effect on crystallinity and optical properties were investigated and compared with first-mentioned adamantyl-ethyl DPP derivative. It was found that the prolongation of the π-conjugation causes significant bathochromic shift of an absorption maximum and the same phenomenon was also observed in emission spectra. The prolongation of π-conjugation also leads to a decrease in the crystallinity of the material; however the X-Ray analysis of the bithiophene adamantyl-ethyl DPP derivative (2) was determined.

Figure 2: AFM image (A), XRD analysis – plane-to-plane stacking (B) and adamantyl-induced packing (C) of derivative 1

References [1] A. Kovalenko, C. Yumusak, P. Heinrichova, et al., Journal of Materials Chemistry C 5 (2017) 4716. [2] M. Naik, N. Venkatramaiah, C. Kanimozhi and S. Patil, The Journal of Physical Chemistry C 116 (2012) 26128. [3] M. Grzybowski and D. T. Gryko, Advanced Optical Materials 3 (2015) 280.

Acknowledgement This work was supported by the Czech Science Foundation grant No.17-24707S. MC thanks to project no. FCH-S18-5331.

133

ANTIBACTERIAL 3D POROUS COLLAGEN SCAFFOLDS FOR SOFT TISSUE

REGENERATION

Jana Dorazilová1, Johana Babrnáková2, Kristýna Šmerková3, Pavel Kopel3, Silvia Kočiová3, Pavel Diviš4,

Vojtěch Adam3, Lucy Vojtová2

1 Brno University of Technology, Faculty of chemistry, Institute for physical and applied chemistry,

Purkyňova 118, 612 00 Brno, [email protected] 2 Brno University of Technology, CEITEC – Central European Institute of Technology, Advanced

polymers and composites, Purkyňova 656/123, 612 00 Brno 3 Mendel University in Brno, Faculty of AgriSciences, Department of chemistry and biochemistry,

Zemědělská 1, 613 00 Brno 4 Brno University of Technology, Faculty of chemistry, Materials Research Centre, Purkyňova 118,

612 00 Brno

Keywords: regenerative medicine, drug release, freeze drying, chitosan, selenium nanoparticles

Collagen is a highly used biopolymer in regenerative medicine, due to its structure reminiscent of extracellular matrix. One of the main issue using collagen-based materials in regenerative medicine is they easy targeting by microbial invasion.

In the presented study, synergistic effect of two types of antibacterial agents, biopolymeric chitosan and selenium nanoparticles (SeNPs), were utilized. The polycationic character of chitosan giving its unique antimicrobial properties, that can be useful in soft tissue regeneration [1]. Antibacterial properties of SeNPs have been reviewed as well [2]. Since selenium is a biogenic element, selenium nanoparticles could serve as an effective substitute for metal-based nanoparticles, e.g. silver nanoparticles. The collagen/chitosan/SeNPs scaffolds were prepared by freeze-drying procedure and their biomechanical properties were improved by chemical crosslinking. Prepared samples differing in the content of antibacterial agents varied significantly in the microstructure. Selenium nanoparticles seemed to speed up the enzymatic degradation in both collagenase and lysozyme. Antibacterial activities of prepared scaffolds showed a positive synergistic effect on bacterial inhibition of both chitosan and SeNPs with the respect to their concentrations as proved by disc diffusion method on gram-positive Staphylococcus aureus and even methicillin-resistant Staphylococcus aureus bacterial strains. Trends of antibacterial activity observed in 24 h corresponded with the trends obtained from release study of selenium nanoparticles.

Based on the presented results, collagenous matrices enriched with chitosan and selenium nanoparticles are

good candidates for the further use as an antibacterial scaffold in the field of soft tissue engineering.

Figure 1: Scanning electron microscopy image of collagen/chitosan scaffold doped with SeNPs (white dots) at lower (up) and higher magnification (down).

References [1] F. Croisier, C. Jérôme, European Polymer Journal 49 (2013) 261-268. [2] D. Chudobova, K. Cihalova et al., FEMS Microbiology Letters 351 (2014) 195-201.

Acknowledgement This work was supported by the CEITEC 2020 (LQ1601) with financial support from the Ministry of Education, Youth and

Sports of the Czech Republic under the National Sustainability Programme II and by the Ministry of Health under the project no. 17-29874A.

134

Polylysine Coated Magnetic Nanoparticles As A Tool For DNA

Isolation From Real Samples

Lenka Fialova1, Alena Spanova1, Bohuslav Rittich1

1 Brno University of Technology, Faculty of Chemistry, Purkyňova 464/118 612 00 Brno,

[email protected]

Keywords: magnetic nanoparticles, poly(L-lysine), DNA isolation, real samples

Solid phase DNA extraction has been shown to be a

simple method for PCR-ready DNA isolation. Poly(L-

lysine) coated iron oxide nanoparticles (MNPs) were not

studied so far. Poly(L-lysine) coated solid surfaces are

positively charged in acidic pH and negatively charged in

alkali pH due to the protonation and deprotonation of

functional groups. This enables the binding of charged

species, including nucleic acids, using electrostatic

interaction between the solid surface and the charged

molecules. First, Nicotiana tabacum DNA capture and

elution was studied with different amounts of poly(L-

lysine) coated magnetic nanoparticles. Buffers with

different acidic pH (4.0 – 6.5) and alcalic pH (7.5 - 10.0)

were tested for DNA capture or elution, respectively

(Figure 1). Next, MNPs were used for isolation of PCR-

ready DNA from plant based foods, in particular from

chokeberry, red currant and plum jams which are rich in

PCR inhibitors (phenolic compounds and polysacharides)

and contain DNA degraded during technological

processing. Differently purified food homogenates were

prepared for DNA isolation. It was found out that the

isolated DNAs contained different amounts of impurities

according to the purification steps used for preparation

of homogenates from different food products. Some

DNAs were successfully amplified in conventional PCR.

Figure 1: The amount of DNA captured (blue) and eluted (red) during the testing of magnetic nanoparticles

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135

Characterization of adsorption properties of probiotic bacteria

Eva Fryšová1, Klára Černá1, Eva Slaninová1, Stanislav Obruča1, Aneta Chytilová1

1 Faculty of Chemistry, BUT, Institute of Food Chemistry and Biotechnology, Purkyňova 464/118

61200 Brno, [email protected]

Keywords: Adsorption, probiotic bacteria, mucin, BATH test

This work deals with the characterization of adsorption properties of selected bacterial strains considered as probiotics.

Probiotic bacteria have a beneficial effect on the health of the host [1]. One of the main criteria of an effective probiotic strain is the ability of adsorption on intestinal mucosa [2]. For this purpose, spectrophotometric method for characterization of adsorption to mucin was optimized in this work. Moreover, the effects on adsorption and characterization of interactions that play a role in adsorption were studied using BATH test and measurement of ζ potential.

The selected probiotic bacteria were representatives of the genus Lactobacillus, Bifidobacterium and Bacillus. These microorganisms were cultured in MRS medium and used when they reached a stationary growth phase. The solution of mucin (from porcine stomach) and hexadecane (for BATH test) were used as adsorbents.

After extensive optimization the optimal conditions were reached, in which the adsorption of model bacteria L. rhamnosus CCM 1825 to mucin was the most significant. Example of selecting the most suitable medium for adsorption to mucin is shown in Table 1. It is clear from table that the most significant adsorption occurred in Tris-HCl buffer. Optimal conditions were then applied to measure mucin adsorption in other selected probiotic bacteria (Figure 1). The results showed, that adsorption to mucin was strain-specific and probably influenced by sensitivity to medium.

Figure 1: Comparison of adsorption to mucin in various probiotic bacteria (LR – Lactobacillus rhamnosus CCM 1825, LP – Lactobacillus plantarum CCM 7039, LA – Lactobacillus acidophilus CCM 4833, LC – Lactobacillus casei CCM 4798, LZ – Lactobacillus zeae CCM 7069, LD – Lactobacillus delbrueckii subsp. bulgaricus CCM 7190, BB – Bifidobacterium breve CCM 7825, BAC – Bacillus coagulans CCM 2658)

Other results showed, that the presence of mucin during cultivation slightly increased the adsorption of L. rhamnosus CCM 1825 and that the optimal temperature of incubation was 37 °C, which is the temperature of human body.

BATH test and ζ potential confirmed the contribution of hydrophobic effect and electrostatic forces on adsorption of selected probiotic bacteria. This contribution was strain-specific. The results showed, that the greater the hydrophobicity of selected bacteria, the lower the ζ-potential.

Table 1: Selection of a suitable medium for adsorption of L. rhamnosus CCM 1825 to mucin, [-] – bacteria did not show adsorption to mucin, red – selected medium

Type of medium Adsorption [%]

Distilled water -

Citrate buffer (100mM, pH 5) -

PBS buffer (pH 7,5) 3,69 ± 0,01

Phosphate buffer (100mM, pH 7,4) 1,15 ± 0,01

Physiological saline solution (0,9% NaCl) -

Glycine buffer (100mM, pH 8,6) 11,94 ± 0,01

Acetate buffer (100mM, pH 4) 18,04 ± 0,01

Tris-HCl buffer (50mM, pH 7,4) 42,03 ± 0,01

References [1] YOO, Ji and Sung KIM, Nutrients 8(3) (2016) 173-193. [2] DALIRI, E.B.-M. and Byong H.-LEE, Food Science and Human Wellness 4(2) (2015) 56-65.

Acknowledgement This work was supported by the project “Materials Research Centre at FCH BUT – Sustainability and Development” No.

LO1211 of the Ministry of Education, Youth and Sports of the Czech Republic and by the project FCH-S-18-5334.

136

THE EFFECT OF ANTIBACTERIAL SELENIUM NANOPARTICLES ON THE

PROPERTIES OF POLYMER-PHOSPHATE BONE FILLERS

Veronika Grézlová1, Lenka Michlovská2, Kristýna Šmerková3, Pavel Kopel3, Vojtěch Adam3, Silvia

Kočiová3, Petr Bábor4, Pavel Diviš5, Petr Poláček2, Lucy Vojtová2

1 Brno University of Technology, Faculty of chemistry, Institute for physical and applied chemistry,

Purkyňova 118, 612 00 Brno, [email protected] 2 Brno University of Technology, CEITEC – Central European Institute of Technology, Advanced

polymers and composites, Purkyňova 656/123, 612 00 Brno 3 Mendel University in Brno, Faculty of AgriSciences, Department of chemistry and biochemistry,

Zemědělská 1, 613 00 Brno 4 Brno University of Technology, CEITEC – Central European Institute of Technology, Preparation

and characterization of nanostructures, Purkyňova 656/123, 612 00 Brno 5 Brno University of Technology, Faculty of chemistry, Materials Research Centre, Purkyňova 118,

612 00 Brno

Keywords: phosphate bone cement, thixotropy, nanoparticles release, rheology, morphology

Today's medicine is able to correct a bone defect or fracture and thus improve patient's health. Calcium phosphate (CaP) ceramics, like as hydroxyapatite and tricalcium phosphate (TCP) are very similar as the inorganic component of natural bone tissue with extraordinary biological compatibility. Synthetic bone cements are used in reconstruction and repair surgery, conservative dentistry, dental implantology, pharmacy etc. However, infection around bone implants (osteomyelitis) is the main problem of modern reconstructive surgery.

In this work polymer-calcium phosphate cement (pCPC) was modified by selenium nanoparticles (SeNPs). Selenium is a biogenic element and exhibits antibacterial properties [1]. As a result, SeNPs improved injectability of bone cement and increased setting reaction rate with the positive effect on cement mechanical properties. Addition of SeNPs into pCPC made the material more thixotropic thus improving the injectability and flowability of the material important for mini-invasive surgery (Figure 1). Moreover, SeNPs accelerated the self-setting pCPC reaction as proved by XRD analysis and affected positively the mechanical strength of the bone filler samples. Morphology showed transformation of amorphous TCP to flower-like crystals. Distribution of SeNPs in pCPC was evaluated by secondary ion mass spectrometry imaging.

Prepared antibacterial cement were very effective on a gram-positive bacteria proved by disc diffusion method

on Staphylococcus aureus and even methicillin-resistant Staphylococcus aureus bacterial strains. The release of SeNPs from bone cement during 48 hours shows, that almost all SeNPs released within 8 hours (96.5 %), which is very promising information since general PMMA bone cements are able to release only 2% of antibiotics.

Due to the positive effect of SeNPs on rheological, mechanical and antibacterial properties, the novel polymer-phosphate bone cement can be possibly applied in mini-invasive surgery as bone filler for the treatment of osteomyelitis.

Figure 1: Thixotropy of original pCPC (black) and SeNPs-modified pCPC (yellow) measured at 23°C by steady-state method using rheometer (AR-G2 TA instrument).

References [1] D. Chudobova, K. Cihalova et al., FEMS Microbiology Letters 351 (2014) 195-201.


Sports of the Czech Republic under the National Sustainability Programme II and CEITEC Nano Research Infrastructure (ID LM2015041).

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137

The comparison of platinum metal contaminations of the

environment in Brno, Czech Republic and Moscow, Russia

Stanislav Ježek1, Renata Komendová1

1 Brno University o Technology, Faculty of Chemistry, Institute of Chemistry and Technology of

Environmnetal Protection, Purkyňova 464/118, 61200 Brno, Czech Republic, [email protected]

Keywords: Platinum, palladium, atomic absorption spectrometry, ICP-OES, soil

The research of this issue was aimed at assessing and comparison the content of platinum and palladium in areas with high density of traffic in the cities of Brno and Moscow.

Intensive automobile traffic in cities is the reason for the release platinum and palladium to the environment. This metals form active layer in the automobile catalysts but there is significant leakage into the surrounding atmosphere during their use. Were analyzed herbaceous vegetation and soil matrix. In view of the simpler diagnostics and more precise determination of the content of platinum and palladium, it is shown that the soil matrix is more suitable for studies of metal contents. In the case of the herbaceous vegetation matrix, the sensitivity of the determination was lower, which may be caused by the interfering influence of other elements or other reasons.

Samples were selected in places with high car traffic - close to the remoteness highways at different distances from the city center.

Graph 1: Regional and long-distance transport of

accumulation in the environment.

Three times higher metal content in the Moscow city center versus Brno city center was detected.

Concentrations of Pt and Pd in samples from MKAD (Moskovskaya Koltsevaya Line avtomobilnaja doroga) were more than 10 times higher than the value from Brno, what is caused by high frequency of car traffic and constantly forming car columns with discontinuous driving style.

The major environmental platinum and palladium pollution is their use in automotive catalyst. Surface of the catalyst is attacked during chemically, physically and rapid alternating redox conditions, high temperature and mechanical wear. This wear leads to emission of platinum and palladium into the surrounding environment. The highest accumulation of these metals is in the vicinity of roads, mainly in the large urban areas. So, just people

living near these busy roads are the most endangered

group in terms of influencing their health by present metals with emergence of possible allergic reactions and other disabilities. As a result of the growth of automobile traffic should be monitored for the amount of platinum and palladium released into the environment.

Graph 2: Parameters affecting the release of platinum

and palladium.

References [1] K. Ravindra, L. Bencs, R. Grieken, Science of The Total Environment, Volume 318 (2004), 1. [2] Y. Wang, Li. Xiaozheng, Procedia Engineering, Volume 45 (2012), 1004. [3] F. Reith, S.G. Campbell, A.S. Ball, A. Pring, G. Southam, Earth-Science Reviews, Volume 131 (2014), 1. [4] M. Wellinger, J. Wochele, S.M.A. Biollaz, Ch. Ludwig, Waste Management, Volume 32 (2012), 1843.

Acknowledgement This work was supported by the institution research plan No. FCH-S-18-5331 from the Ministry of Education, Youth and


Autocatalys

Type of catalyst

Catalyst age

Driving speed

Condition of vehicle

Weather conditions

Type of motor

138

Improving the Stability of Perovskite Solar Cells

Matouš Kratochvíl1, Dávid Strachala2, Adam Gajdoš2, Martin Weiter1

1 Faculty of Chemistry, Brno University of Technology, Purkyňova 464/118, 612 00 Brno, Czech

Republic, [email protected] 2 Faculty of Electrical Engineering and Communication, Brno University of Technology, Technická

3058/10, 616 00 Brno, Czech Republic

Keywords: photovoltaics, perovskite, solar cells, stability, moisture

In the field of renewable energy sources, perovskite solar cells are one of the most studied topics in recent years. Solar cells using perovskite materials as active layer have shown great potential with reported record efficiencies over 20 %. However the prospect of producing cheap and environmentally friendly perovskite solar cells is hampered by several issues. Namely it is presence of lead in perovskite materials, possessing possible harmful effects on health, and poor stability of perovskite solar cells.

One of the main stability issues is tendency of used perovskites to decompose in presence of moisture, rendering them inactive [1].

In order to increase the overall stability of prepared devices we studied the effect of moisture on perovskite degradation. Controlled moist environment was achieved in climatic chamber. Changes in perovskite’s crystal structure were determined by XRD measurements and related surface morphology was studied by AFM and SEM. Influence of moisture on overall performance of perovskite solar cells was studied by current-voltage and impedance characterization.

With the aim to improve solar cells’ resistance to moisture we studied possibility of use of fatty acids, particularly oleic acid, as passivation layer. Outcomes of this study will be presented as well.

References [1] G. Niu, X. Guo, L. Wang, J. Mater. Chem. A 3 (2015) 8970.

Acknowledgement M. Kratochvíl was supported by the FCH BUT under project No. FCH-S-18-5194 and by Southmoravian Region through

Brno PhD. Talent program. M. Kratochvíl and D. Strachala gratefully acknowledge financial support under BUT project No. FCH/FEKT-J-18-5427. D. Strachala was supported by FEEC BUT under project No. FEKT-S-17-4595. A. Gajdoš was supported by FEEC BUT under project No. FEKT-S-17-4626 Research infrastructure was supported by National Program for Sustainability I (MEYS CR), projects No. REG LO1211 and LO1210.

139

Thermal properties of electro insulating papers

Lucie Marackova1, Veronika Melcova2, Josef Samek3, Oldrich Zmeskal4

1 Brno University of Technology, Faculty of Chemistry, Purkynova 118, 612 00 Brno, Czech Republic,

[email protected] 2 Brno University of Technology, Faculty of Chemistry, Purkynova 118, 612 00 Brno, Czech Republic 3 Brno University of Technology, Faculty of Electrical Engineering and Communication, Technicka

10, 616 00 Brno, Czech Republic 4 Brno University of Technology, Faculty of Chemistry, Purkynova 118, 612 00 Brno, Czech Republic

Keywords: electro insulating papers, transient spectroscopy, thermal properties

Electro-insulating papers for use in electromotor are typically produced by gluing several thin layers of different materials. The paper thickness is typically 0.1 to 0.5 mm. The operating temperature of the films is up to 250 °C, so the thermal properties also play an important role. This paper deals with the study of thermal properties of selected papers (NKN, DMD, TFT and TVAR), see Table 1.

Table 1: Basic properties of selected electro insulating papers

type structure thickness (mm)

mass (g)

NKN Nomex-Capton-Nomex 0.2 1.25

DMD Dacron-Mylar-Dacron 0.3 2.27

TFT TufQUIN TFT 0.2 1.50

TVAR ThermaVolt AR 0.1 0.90

The typical responses for step wise heating |(cooling)

of planar sample DMD and their differences with respect to the maximum (minimum) value are shown in Figure 1.

Figure 1: Transient responses T1, reference temperature T0

and the differences Tc due to the steady values

The basic thermal parameters (thermal conductivity, specific heat, and thermal diffusivity) can be determined from these transients [1, 2]. The thermal conductivity can

be derived from Fourier law Tλ=q grad as [3]

)Δ()( TPSh=ShΛ=λ ,

where T is difference of temperature between heat side

and cold side of the sample, UI=P is power of electric

heat source, S is area and h is thickness of the sample. Specific heat capacity cp can be derived from

calorimetric equation TmcQ dd p , where tP=Q dd is

quantum of heat needed to heating of unitary mass of material by the temperature dT [3]

1p )d(d)(

tTmP=c

where m is the mass of the measured material.

Thermal conductivity thermal diffusivity a, and specific heat capacity cp are finally related by the

equation ac p , where is density of measured

material. The determined values of these parameters are in the Table 2.

Table 2: Thermal parameters of measured materials type (kg/m3) W/m/K) c (J/kg/K) a (mm2/s)

NKN 868 0.178 1620 0.126

DMD 1050 0.135 1213 0.106

TFT 1042 0.129 1442 0.086

TVAR 1250 0.113 1380 0.066

Results of specific heat capacity were verified by the

measurement of differential scanning capacity (Figure 2)

Figure 2: DSC spectra of measured samples

References [1] H.S. Carslaw and J.C. Jaeger, Conduction of Heat in Solids, 2. Ed. Clarendon Press, London (2003), pp. 510. [2] O. Zmeskal, P. Stefkova, L. Dohnalova, R. Barinka, Int. J. Thermophys. 34 (2012) 926–938 [3] K. Pechackova, P. Florian, Z. Pavlik, and O. Zmeskal, in Thermophysics 2018: 23rd International Meeting of

Thermophysics 2018, AIP Conference Proceedings, Ed I. Medved et al., AIP, Melville, NY, 2018, in press.

Acknowledgement Authors thank to Ministry of Education, Youth and Sports of Czech Republic for support by project Sustainability and

Development REG LO1211 addressed to Materials Research Centre at FCH BUT.

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140

SINGLE CELL ANALYSIS AND USE OF AUTOFLUORESCENCE IN PHA

SYNTHESISING BACTERIA

Lucie Müllerová 1,2, Stanislav Obruča 1,2, Filip Mravec 1, Kateřina Bílková 1

1 Materials Research Centre, Faculty of Chemistry, Brno University of Technology, Brno, Czech

Republic 2 Institute of Food Science and Biotechnology, Faculty of Chemistry, Brno University of Technology,

Brno, Czech Republic

Keywords: bacterial autofluorescence, Cupriavidus necator, flow cytometry, fluorescence,

fluorescence microscopy, polyhydroxyalkanoates

It has been assumed that cellular populations were homogenous but in the last few years, by using methods like flow cytometry, it has been shown that it is not the case. Certain subpopulations with various changes in the cell size, PHA content, enzymatic levels exist in what may seem a homogenous population of cells. Fluorescence techniques using combination of fluorophores and mainly cellular autofluorescence are the main methods in our research when differencing between subpopulations.

Cellular green autofluorescence caused predominantly by flavins can affect the sensitivity of fluorescence microscopic or flow cytometric analyses by interfering with the detection of low-level specific fluorescence. We intend to use flavins’ autofluorescence to distinguish microbial cells from abiotic particles in flow cytometry analysis and it can even serve as a marker of physiological state of the microbial culture of the interest, for instance during biotechnological process.

Figure 1: Histograms of C. necator H16 autofluorescence that show significant changes in time (30 min intervals) when exposing cells to 100mM oxygen peroxide.

Therefore, one of our aims is to use the green autofluorescence of bacteria Cupriavidus necator H16

which is considered being industrial candidate strain for polyhydroxyalkanoates (PHA) production and its mutant strain Cuprivaidus necator PHB-4 unable of PHA accumulation as a viability marker in various biotechnological processes.

PHA synthesised by Cupriavidus necator H16 is not only a very attractive material because of its biodegradable characteristics, but as we found out, it can also act as a protectant when cells are exposed to oxidative stress. In several experiments we have shown that single cell analysis can give us data eg. on cells’ viability, amount of PHA and many more, very quickly.

In other experiments employing fluorescence life-time imagining microscopy, we found exactly two fluorescence average lifetimes of cellular

autofluorescence (1= 0.8–1.2 ns, 2= 3.5–4.2 ns) that were present in every sample we analysed and these can also be used when monitoring bacterial populations.

Flow cytometry and fluorescence microscopy are complementary techniques used in this work. Combining their strengths, i.e. the ability of flow cytometer to analyse millions of cells in a very short time, and the high resolution of fluorescence microscopy when analysing a single cell, we are able to obtain much more reliable data than when using just one of these techniques.

Figure 2: Left: Two fluorescence average lifetimes,

1= 0.8–1.2 ns (green), 2= 3.5–4.2 ns (red) Right: Cupriavidus necator H16, BODIPY 493/503 was used to dye the PHA granules (red, average lifetime about 5 ns) and cellular autofluorescence is green.

Acknowledgement

This study was funded by the project “Materials Research Centre at FCH BUT - Sustainability and Development” No. LO1211 of the Ministry of Education, Youth and Sports of the Czech Republic and by the project FCH-S-18-5334.

141

THE USE OF NATURAL EXTRACTS IN COSMETICS AND SUBSEQUENT DETECTION OF

PLANT DNA USING MOLECULAR DIAGNOSTIC METHODS

Renata Pavelková1, Denisa Romanovská2, Monika Plachá2, Anna Plášková2, Petra Matoušková1,

Andrea Hároniková1, Ivana Márová1

1 Materials Research Centre, Faculty of Chemistry, Brno University of Technology, Purkyňova 464

/118,612 00 Brno, [email protected] 2 Institute of food science and biotrechnology, Faculty of Chemistry, Brno University of Technology,

Purkyňova 464 /118, 612 00 Brno

Keywords: natural extracts, encapsulation, cosmetic products, PCR

It is known that oxidation reactions could produce free radicals, which can start chain reactions that will damage skin cells. Increasing the amount of free radicals could initiate the wrinkling, photoaging, elastosis, drying, and pigmentation of the skin [1]. Plants can be used as sources of broad spectrum of active compounds. Some of them have antioxidant activity and are preferably used in cosmetics for improving skin care [2].

Presented work is focused on application of natural extracts in cosmetics. Firstly, water and ethanol extracts were prepared. Spectrophotometric analysis of active compounds has been done in terms of polyphenols, flavonoids in green beans extract from Coffea arabica and carotenoids and chlorophylls in microalgae Arthrospira and Dunaliella salina extracts. Antioxidant activity was evaluated in extracts from both natural sources. For better stability in cosmetic formulation, the extracts were encapsulated into liposome particles. Encapsulation efficiency was determined by total polyphenols or total carotenoids entrapped in particles. Particle size and size

distribution were analyzed by dynamic light scattering and colloid stability of particles by zeta-potential. Some emulsions of the oil in water type with natural extracts were prepared. Analytical centrifuge was used for testing stability of resulting emulsion. Finally, the prepared emulsions with plant extracts were evaluated by molecular diagnostic methods.

Our goal was to prepare emulsions enriched by active compounds from green coffee beans and micro algae to diminish free radicals effect on the skin. Encapsulation of extracts into liposomes was successful and particles were stable and suitable for further application. Analytical centrifuge showed that prepared emulsions were stable and potentially applicable as skin care products. Analysis of plant DNA isolated from green coffee beans, microalgae and prepared extracts and emulsions showed that isolated DNA was in quality allowing its PCR amplification. Using the PCR analysis, the presence of added ingredient of natural plant origin was verified.

References [1] I. Kusumawati, G. Indrayanto, Studies in Natural Products Chemistry 40(2013) 485-505. [2] M. B. Ariede, T. M. Candido, Algal Research 25 (2017) 483-487.

Acknowledgement This work was also supported by the project “Materials Research Centre at FCH BUT—Sustainability and Development”

no. LO1211 of the Ministry of Education, Youth and Sports of the Czech Republic.

142

Screening of biosurfactants excretion among selected bacteria

Iva Pernicová1,2, Olga Kratochvílová1, Dan Kučera1,2, Stanislav Obruča1,2

1 Faculty of Chemistry, Brno University of Technology, Institute of Food Chemistry and

Biotechnology, Purkyňova 464/118 61200 Brno, [email protected] 2 Materials Research Centre, Faculty of Chemistry, Brno University of Technology, Brno, Czech

Republic

Keywords: Biosurfactants, polyhydroxyalkanoates, screening method

This work deals with screening method of detection of biosurfactants which are produces by bacteria capable of accumulation of polyhydroxyalkanoates.

Biosurfactants are surface active substances which are produced by various microorganisms. These biosurfactants do not burden the environment because they are non-toxic and biodegradable compared to oil-based surfactant. Another advantage of biosurfactants is also their effectiveness under various conditions (higher temperature, acid or alkaline pH or higher salinity). Moreover, they can be produced from renewable resources. Biosurfactants are widely used; they can be used in bioremediation, healthcare, cosmetics, agriculture and food [1].

Polyhydroxyalcanoate (PHA) are microbial polyester which are biodegradable and biocompatible. Moreover, PHA are a suitable alternative the commonly used plastics produced from petrochemical resources and they can be also produced from renewable source. Their used are wide such as bottles, packaging, and scaffolds for drugs or hormones targeted delivery [2].

PHA are bacterial intracellular product and biosurfactants are extracellular product (Figure 1). The great advantage of linking these two biotechnology processes is cost reduction due to two products within a single production.

Figure 1: Idea of production of biosurfactants by bacteria accumulation of PHA

Various methods have been tested to identify bacterial strains capable of producing biosurfactants (Table 1).

Table 1: An overview of methods Methods Repeatability Amount of

sample Rate of analysis

Oil spreading assay ++ µl min

Emulsification capacity

assay

+ ml day

Solubilization of

crystalline anthracene

+ ml day

CTAB agar assay + µl day

Method Du-Nouy-Ring ++ ml min

Orcinol method - µl day

Then the production of biosurfactants in complex and

mineral medium was compared. Selected bacteria optimized the production medium by the addition of yeast autolysate and oil. For the extraction of the biosurfactants, a suitable solvent was first selected and after their extraction they were characterized by infrared spectrometry and thin layer chromatography.

References [1] Santos D.K.F., Rufino R.D., Luna J.M., Santos V.A., Sarubbo L.A.: International Journal of Molecular Sciences, 17(3),

(2016) 401 [2] Obruca S., Marova I., Svoboda Z., Mikulikova R., Folia Microbiologica, 55(1) (2010), 17-22

Acknowledgement This study was funded by the project “Materials Research Centre at FCH BUT - Sustainability and Development” No.

LO1211 of the Ministry of Education, Youth and Sports of the Czech Republic and by the project FCH-S-18-5334.


143

Stability of methylated humic acids

Jan Rybárik1, Vojtěch Enev1, Martina Klučáková1

1 Materials Research Centre, Faculty of Chemistry, Brno University of Technology,

Purkyňova 464/118, 612 00 Brno, Czech Republic

Keywords: Humic substances, methylation

Humic substances represent a wide range of organic compounds generated by gradual decomposition of plant residues and dead organisms in ecosystems. They are among the most widespread compounds in the world that contain a huge amount of carbon in its structure. Is contains a lot of funkcional groups and mainly carboxyl COOH group.

Humic substances are able to bind various pollutants from Industrial production, agriculture and other human activities (like heavy metals, pesticides, herbicides, dyes, etc.). The interaction possibilities can be different: ion exchange, hydrogen bridge formation, coulombic interactions, hydrogen bridges, van der Waals interactions, hydrophobic interactions, etc. Humic acid methylation is often used to investigate the effect of the carboxyl group and as well use for our experiments. We decided to find out if the methylation of the carboxyl groups even after being dissolved in aqueous low sodium hydroxide solution. (0.05M NaOH) Due to selective methylation (with TMSD -trimethylsilyldiazomethane) were blocked COOH groups that are primarily responsible for Coulomb interactions. This sample of methylated humin acid has a brownish tinge then the black sample of humic acid (Figure 1).

Figure 1: Color difference between humic acid (left) and methylated hmumic acid

Methylation was performed by the ATR method on FT-IR on a Nicolet iS50 spectrophotometer. On the graph )Figure 2) you can see simple of humic acid and methylated humic acid.

Methylated humic acid is less soluble. The humic acid is dissolved in 0.01M NaOH, but a stronger concentration of NaOH (0.05M) is needed for methylated humic acid.

Figure 2: Graph of FTIR – humic acid (blue) and methylated (red)

There were 4 identical samples of dissolved mHK at a concentration of 0.2 g/L. Four methods were used to recover methylene humic acid from the solution. The obtained samples were re-measured on the ATR method on FT-IR on and the Nicolet iS50 spectrophotometer.

1. Dissolution of methylene acid and immediate

precipitation of humic acid with concentrated HCl to pH = 1, centrifugation, lyophilization

2. Extraction of the methylene acid humic sample with dilute humic acid to pH = 3, centrifugation, washing with MQ water and lyophilization

3. Lyophilization of the sample without prior precipitation with acid

4. Free evaporation of water on a petri dish in an oven at 40 ° C

Figure 3: Graph of FTIR –4 simples of mHK – blue (pH =1), brown (pH=3), green (free evaporation) yellow (only lyophilization)

It can be seen in figure 2, the methylation of functional groups resulted in changes of FT-IR spectra characteristic for esters. The intensity of the broad peak at around 3500 cm

−1 was decreased by methylation and

the shallow band at 2580 cm−1

was completely absent. The absorption band corresponding to C=O stretching was shifted to higher wavenumbers after methylation (from 1720 cm

−1 to 1735 cm

−1) and its intensity was

increased. These changes we miss in all of 4 simples in figure 3. Due to our measurement we can confirm, that is methylation of humic acid isn´t stabile in weak solution of NaOH.

Acknowledgement The Materials Research Centre at the Faculty of

Chemistry, Brno University of Technology is supported by project No. LO1211 from the Czech Ministry of Education, National Sustainability Program I.

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144

Organic Transistors Towards Bio-electronic Applications

Stanislav Stříteský1, Lukáš Omasta1, Jiří Ehlich1, Šárka Tumová1, Aneta Marková1, Eva Šafaříková2, Jan

Víteček2, Lukáš Kubala2, Lubomír Kubáč3, Ota Salyk1, Martin Vala1, Martin Weiter1


Republic; e-mail: [email protected] 2 Institute of Biophysics AS CR, Královopolská 135, 612 65 Brno, Czech Republic 3 Centrum Organické Chemie, Rybitví 296, Rybitví 533 54, Czech Republic

Keywords: Organic transistors, organic semiconductors, PEDOT:PSS, Diketo-pyrrolopyrroles,

Biosensors, OECT, OFET

In recent years, several approaches have been developed to biologically relevant sensing of analytes or to the diagnosis of living cells. For these applications, there is considerable demand for small portable and low-cost devices that can be used under clinical conditions.

Organic semiconducting materials can provide higher sensitivity of transistors compared to conventional devices and allow the use of different architectures than standard semiconductor transistors (MOSFETs) such as ion-sensitive organic field transistors (ISOFETs), organic electrochemical transistors (OECT) and electrolyte grounded transistors (EGOFET). This ability is very attractive to create a functional interface with living cells.

Biocompatibility study (Fig. 1) and study of the electrical properties of poly(3,4-ethylenedioxythiophe-ne):poly(styrene sulfonate) (PEDOT:PSS) [1,2] and organic semiconductors were performed.[3]

It has been found that PEDOT:PSS thin films without additive or any thin film after treatment provide limited conductivity and stability for use in biomedical applications. Addition or subsequent treatment with ethylene glycol in combination with thermal annealing provided thin layers with electrical resistance and stability sufficient for use in sensing animal cell physiology.

The electrical properties of DPP were studied using the OFETs transistor model. In particular, it has been investigated under what conditions the maximum mobility of the charge carrier can be achieved. By using the cumulative effect of self-assembled monolayers on dielectrics and electrodes and detailed thermal analysis of DPP, higher charge carrier mobility than previously (5.5· 10

-3 cm

2/Vs) was achieved. [4]

Figure 1: The biocompatibility assay of PEDOT:PSS inks (upper series of photo: A-E) and organic semiconductors (bottom series of photo: A-stadnard culture dish, B-glass, C-Pentacene, D-DPP, E-P3HT, F-PEDOT:PSS) [1,3]

References [1] Stříteský S. et al, J BiomedMater Res Part A 2018:106A:1121–1128.[DOI: 10.1002/jbm.a.36314] [2] Salyk O. et al. Applied Sciences 2017, 7(10), 998 [DOI: 10.3390/app7100998] [3] Šafaříková E. et al, Sensors and Actuators B 260 (2018) 418–425 [DOI: 10.1016/j.snb.2017.12.108] [4] Stříteský S. et al. Chem. Pap. (2018) [DOI: 10.1007/s11696-018-0479-6]

Acknowledgement The work was supported by the Czech Science Foundation, project no. REG 17-24707S. Jiří Ehlich and Šárka Tumová

were supported by the Faculty of chemistry BUT under project No. FCH-S-18-5194. Research infrastructure was supported by National Program for Sustainability I (MEYS CR), project no. REG LO1211.

ORCID iD QR Code

145

Monitoring of the fatty acid content in Swiss type cheese

Michal Sýkora, Eva Vítová

Faculty of Chemistry, Brno University of Technology, Department of Food Chemistry and

Biotechnology, Purkyňova 118, 612 00, Brno, Czech Republic; [email protected]

Keywords: cheese, fatty acids, SPE, GC-FID

Cheese is generally defined as “a milk product made by precipitation of milk protein from milk by the use of rennet or other suitable coagulating agents, by the acidification and separation of the whey content” and matured cheese as “cheese which has been subjected to further biochemical and physical processes” (Directive 397/2016 Coll. (2016)).

Swiss type cheese is a generic name for several related varieties of cheese, which resemble Emmental cheese, a yellow, medium-hard cheese that originated in the area around Emmental, Switzerland [2]. Most types of Swiss cheese have a distinctive appearance, as the blocks of the cheese are riddled with holes (0,5-1,5 cm) known as “eyes”. Swiss cheese without eyes is known as “blind” [1]. “Moravský blok/bochník” is a Swiss type cheese with a few or no eyes of Czech origin.

Fatty acids represent important part of sensory active compounds that contribute to the flavour of cheese. They are carboxylic acids with long aliphatic chain, either saturated or unsaturated. Fatty acids in cheese are mostly part of triacylglycerols and/or phospholipids, if not bound they are called free fatty acids [3].

Current trends show that gas chromatography comes as very convenient method to assess both bound and free fatty acids. Combined with other isolation/separation techniques such as solid-phase extraction, microextraction and thin-layer chromatography comes a great tool to identify and quantify fatty acids in various matrices [4].

The aim of this study was to identify and quantify free and bound fatty acids in model samples of the Swiss type cheese (Moravský bochník). Model samples were produced at laboratory (pilot plant) conditions at Tomas Bata University in Zlín using a standard technological procedure. Commercial samples (Emmental cheese and Moravský bochník) were purchased at the local market.

The ČSN EN ISO 1735:2005 method was chosen for the lipid extraction from cheese samples. Solid-phase extraction and thin-layer chromatography were compared for fractionation of lipids and to obtain especially fraction of free fatty acids. Present free and bound fatty acids were then converted to methylesters using methanolic solution of bortrifluoride (ČSN EN ISO 12966-2:2011) and assessed by gas chromatography with flame ionization detection.

In total, 32 bound and 20 free fatty acids were identified in cheese samples, with the highest amount of caproic, caprylic, capric, lauric, myristic, palmitic, stearic and oleic acids. In the commercial samples concentrations of both bound and free fatty acids were similar. Comparing commercial vs. model samples, model samples had significantly higher concentrations of both free/bound fatty acids than purchased ones, which leads to higher amount of sensory active compounds and consequently probably to better sensory characteristics. Both commercially produced Swiss type cheeses had bland taste, probably owing to their often-practical use as a matrix for processed cheese production.

References [1] R.E. Liggett, M.A. Drake, J.F. Delwiche, Journal of Dairy Science 91 (2008) 466. [2] A. Prandini, S. Sigolo, G. Piva, Journal of Food Composition and Analysis 24 (2011) 55. [3] S. Kaminarides, P. Stamou, T. Massouras, Food Chemistry 100 (2007) 219. [4] M. E. Johnson, Journal of Dairy Science 100 (2017) 9952

Acknowledgement This work was supported by a Standard project of specific research No. FCH-S-18-5334.


146

Study of potencial use and production of carotenoid, lipid enriched

biomass using extremophilic algae isolated from Rio Tinto, Spain

Martin Szotkowski, Carlos Vilchez Lobato, Ivana Márová

Brno University of Technology, Faculty of Chemistry, Institute of Food Science and Biotechnology and

Materials Research Centre, Purkyňova 464/118, Brno 612 00, [email protected]

Carotenoids are a group of natural pigments and antioxidants that have been used in pharmaceutical, food and agricultural industries. Lipids fill a number of essential functions in the cell and are also a rich source of energy. Their high energy potential can also be used in the petrochemical industry to produce biofuels in the form of fatty acid methyl esters. Their current production uses agricultural crops as a source and huge areas of agricultural land that could be used to produce food for the human population. For this reason, scientists have focused on exploiting the potential of microorganisms for producing the above-mentioned substances.

One of the most promising groups are phototrophic microorganisms, whose cultivation promises to reduce costs in the form of open outdoor cultivations. The generally known disadvantage of used algae and

cyanobacteria is their slow growth and the associated susceptibility to contamination by other strains of microorganisms. For this reason, a number of projects focusing on this issue have focused on optimizing production in closed bioreactors which have greatly reduced the problem of contamination. On the other hand, however, the costs associated with this production are very high and block the possibility of more efficient use of algae for the production of carotenoids and lipids. One of the most promising ways of using outdoor cultivations and thus reducing production costs is the use of extremophilic algae strains. This work presents the study of production properties and optimization of the cultivation conditions of the acidophilic strain Coccomyxa onubensis isolated from the Rio Tinto river in the Andalusian region of Spain, in order to maximize the production of carotenoids and lipids.


147

Removal of sulfonamides antibiotics by wood-decay fungi from

water matrix

Suková Petra1, Žižlavská Adéla2, Švestková Tereza1, Vávrová Milada1

1 Brno University of Technology, Faculty of Chemistry, Purkynova 118, Brno 61200, Czech Republic 2 Brno University of Technology, AdMaS Centre, Faculty of Civil Engineering, Purkynova 139, Brno

61200, Czech Republic

Environmental contamination by residues of pharmaceuticals is widespread world-wide problem. Significant point sources of pollution are wastewater treatment plants (WWTPs). Conventional WWTPs are insufficient to treat micropollutants by used technology and they discharged treated wastewater to the recipients where it contaminates surroundings water ecosystem.

One of the most discussed group is antibiotic due to their potential for bacterial resistance. In our work, we are focusing on sulfonamides antibiotics which are widely used as human and veterinary antibiotics in the Czech Republic. Six representants from sulfonamides antibiotic (sulfapyridine, sulfadiazine, sulfamethoxazole, sulfathiazole, sulfamerazine and sulfamethazine) were chosen for experiments.

Nowadays, they are discussed several possibilities for removal of xenobiotic residues from water matrix.

One of them is the utilization of wood-decay fungi potential due to their unspecific oxidative enzymatic system. Especially Trametes Versicolor, as representatives of white root fungi, has shown promising efficiency for degradation of micropollutants.

For the experiments, drinking and wastewater from outflow from WWTPs were used. Both were spiked by sulfonamides antibiotics. Due to very complex matrix, it was necessary to optimize cleaning step which was carried out by solid-phase extraction (SPE). High-performance liquid chromatography (HPLC) coupled to mass spectrometry detector (MS) were used for the identification and quantification of selected analytes.

grant No. FCH-S-18-5331 and under the project No. LO1408 „AdMaS UP - Advanced Materials, Structures and Technologies“, supported by Ministry of Education, Youth and Sports under the „National Sustainability Programme I“.

148

Modelling of Bioelectronic devices

Truksa, J.


The topic of this thesis is computer modelling of an organic electrochemical transistor (OECT). To create such a model, the electric field and ion concentration were numerically computed, using the finite element method. The electric potential on top of the OECT channel, the changes in conductivity and the output current of the OECT were computed. To carry out the computation, a standard personal computer and the commercial

software COMSOL Multiphysics were utilized. Due to a lack of computational power, the model had to be split into parts and drastically simplified. The presented results differ from those in literature, as the saturation of the transistor is not modelled correctly. This deviation from real OECT behaviour is likely caused by the simplification of the model.

149

Modification of PEDOT:PSS Surface by RGD Peptide

Šárka Tumová1, Romana Malečková1, Vojtěch Enev1, Stanislav Stříteský1, Martin Vala1, Martin

Weiter1


Republic

Keywords: PEDOT:PSS, RGD peptide, sulfo-SANPAH, biocompatibility, contact angle

Conductive polymers show a big potential in a biomedical applications thanks to their good electrical and optical properties, unique mixed electronic and/or ionic transport properties and combination of structural and functional flexibility, which allows to design organic material with desirable properties. One of the most promising conductive polymers is polythiophene derivative PEDOT (poly(3,4-ethylenedioxythiophene)). This polymer differs from the others by a higher electrical conductivity and chemical stability. PEDOT doped with poly(styrene sulfonate) anions (PEDOT:PSS) is the most-commonly used material in organic electronics. However, the disadvantages such as poor biocompatibility or hydrophobicity restricted its further biomedical applications.

This work was focused on the modification of PEDOT:PSS surface by the arginine-glycine-aspartic (RGD) acid peptide for the purpose to increase its biocompatibility and hydrophilicity. This peptide is used to modify surface of different materials for the improvement of the cell adhesion and proliferation [1–5]. To conjugate RGD peptide to the surface of PEDOT:PSS, a bifunctional photolinker sulfo-SANPAH was used [4]. The modified surface was characterized by measurement of contact angle and subsequent calculation of surface energy including its dispersive and polar component, see Table 1. Pure glass was used as a reference substrate as it was proved that photolinker sulfo-SANPAH reacts with hydroxyl groups of the surface of material [4]. The results showed increased surface energy after modification in the case of both substrates, where the value after modification is approximately the same in both cases. This positive influence on the hydrophilicity of material after RGD modification

was already published in several papers [6–8], which indicates the process of modification was successful.

Table 1: Table of surface energies obtained for glass substrate, glass substrate modified by RGD peptide, polymer PEDOT:PSS and PEDOT:PSS modified by RGD peptide

Surface energy

[mN.m-1] Dispersive energy

[mN.m-1] Polar energy

[mN.m-1]

glass 55 ± 8 18 ± 3 37 ± 7

glass /RGD 68 ± 2 17 ± 0,5 51 ± 2

PEDOT:PSS 62 ± 4 18 ± 3 45 ± 6

PEDOT:PSS/RGD 66 ± 3 15 ± 1 52 ± 4

To confirm the successful modification of polymer’s

surface, the modified material was also characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and by Raman spectroscopy. PEDOT:PSS was used as a reference. Obtained infrared and Raman spectra of modified polymer differs from the reference by peaks corresponding to the vibration of –N-H bonds in amines and amides and –O-H groups in –COOH groups, which indicates presence of peptide.

The modified polymer was also characterized by elemental analysis. PEDOT:PSS was used as a reference. Obtained results showed presence of nitrogen in modified polymer while the reference did not contain this element.

All of the obtained results indicated the conjugation of RGD peptide to the PEDOT:PSS surface was successful. It was also confirmed that the modification positively influence the hydrophilicity of polymer. The next study will be focused on the issue whether this modification improves the biocompatibility of conductive polymer PEDOT:PSS.

References [1] H.S. Seo, Y.M. Ko, J.W. Shim, Applied Surface Science, 257 (2010) 596-602. [2] Ch. Yang, K. Cheng, W. Weng, Journal of AMterials Science: Materials in Medicine, 20 (2009) 2349-2352. [3] X. Zhang, J. Gu, Y. Zhang, Journal of Wuhan University of Technology, 29 (2014) 626-634. [4] B. Li, J. Chen, J. Wang, Journal of Biomedical Materials Research Part A, 79A (2006), 989-998. [5] X. Cao, W. Yu, J. Qui, Journal of Material Science: Materials in Medicine, 23 (2012) 527-536. [6] W. Zheng, D. Guan, Y. Teng, Chinese Science Bulletin, 59 (2014) 2776-2784 [7] Y. J. Yang, Y. Kwon, B. Choi, Biomacromolecules, 15 (2014) 1390-1398 [8] Y. Ch. Shin, J. Kim, S. E. Kim, Regenerative Biomaterials, 4 (2017)

Acknowledgement The work was supported by the Czech Science Foundation, project No. REG 17-24707S and by the Faculty of chemistry

BUT under project No. FCH-S-18-5194. Research infrastructure was supported by National Program for Sustainability I (MEYS CR), project no. REG LO1211.

150

THIXOTROPIC POLYMER-COMPOSITE BONE CEMENT

Kristýna Valová1, Lenka Michlovská2, Klára Částková3, Lucy Vojtová2

1 Brno University of Technology, Faculty of Chemistry, Institute of Materials Science, Purkyňova

118, 612 00 Brno, [email protected] 2 Brno University of Technology, CEITEC – Central European Institute of Technology, Advanced

polymers and composites, Purkyňova 656/123, 612 00 Brno 3 Brno University of Technology, CEITEC – Central European Institute of Technology, Advanced

Ceramic Materials, Purkyňova 656/123, 612 00 Brno

Keywords: calcium phosphate cement, injectable bone paste, biodegradable polymer, rheology,

thixotropy

Calcium phosphate cement (CPC) has been a subject of interest in bone tissue engineering for over 30 years. It is hydraulic cement composed of calcium orthophosphate, which forms a mouldable paste after mixing with the liquid phase. The paste is capable of self-setting in vivo at physiological conditions (ionic and enzymatic environment, 100% humidity and 37 °C). One of the main positive of CPC is its injectability, which predisposes the cement to application via mini-invasive surgical procedures. For this reason, they have a great potential in the field of orthopaedics, traumatology (fracture fixation) or dentistry. Each of these applications needs different requirements in particular for biomechanics. The advantage of CPC is the ability to tailor its properties (rheological, structural, mechanical or bioactive) to meet specific application. In order of mini-invasive surgery application, the bone cements need to exhibit the best rheological properties such as injectability, cohesion, or setting time. There are several ways to reach these features. One way is to modify the CPC by a thixotropic polymer affecting the above mentioned properties.

The aim of the work was to compare rheological properties of commonly used water-based CPC with CPC modified by thixotropic thermosensitive copolymer using both dynamic and steady state rheological analysis.

It was found that the thermosensitive copolymer significantly influenced thixotropic behaviour of the cement resulting in its very good injectabilty important for mini-invasive surgery. However, when water has been used instead of copolymer for CPC preparation, poor consistency of the paste was found after high shear stress applying, where the cement tended to form a very dense cluster. In comparison, cement containing 20% solution of the copolymer remained homogeneous throughout the shear rate range experiment (see Figure 1).

Figure 1: CPC samples after steady state rheological measurement. Water + CPC (left), polymer + CPC (right).

Moreover, thermosensitive copolymer improve CPC cohesion keeping the cement at the certain position after the CPC injection into the bone defect place at 37°C (Figure 2). The CPC self-setting process is therefore tuneable by copolymer concentration, affecting both starting setting time (processability) and setting speed. Based on the results, copolymer-modified CPC seems to be useful as injectable bone cements for mini-invasive surgery.

Figure 2: Injectable CPC samples proving good cohesion at simulated physiological conditions (PBS, 37°C).


Sports of the Czech Republic under the National Sustainability Programme II and by the Ministry of Health under the project

no. NV18-05-00379.

151

On Mixing and Separation During Polyhydroxyalkanoates Extraction

– Yield and Purity Optimization

Martin Vanek1, Libor Tomala2, Martin Szotkowski1, Ivana Novackova1, Stanislav Obruca1

1 Brno University of Technology, Faculty of Chemistry, Department of Food Chemistry and

Biotechnology, Purkynova 118, Brno 612 00, Czech Republic, [email protected]

2 Brno University of Technology, Faculty of Chemistry, Department of Material Chemistry,

Purkynova 118, Brno 612 00, Czech RepublicKeywords: polyhydroxyalkanoates, chloroform

extraction, impellers, cavern formation, phase inversion, Cupriavidus necator

Polyhydroxyalkanoates (PHAs) are biodegradable thermoplastic polymers naturally produced by various organisms. Cupriavidus necator, which biomass was extracted in this work, is one of the most promising sources. In conjunction with utilizing waste substrates (e.g. used cooking oil) it offers cheap and near-to-zero carbon emission concept. Unfortunately the most economic form of production, which enables PHAs to be competitive with oil-derived plastics, utilizes halogenated hydrocarbons like chloroform. This means full recycling of solvent used in technology to prevent environmental harm. In case of accident, apart from all precautions, the amount of such solvent kept in factory need to be minimized, which means perfect optimization of all processes involved.

Optimizing the amount of chloroform needed for effective extraction of unit amount of biomass is also important for product purity. Polymer purity is very important for numerous applications, typical example are biomed applications. Unfortunately traditional polishing treatments (hydroxide or hypochlorite solution) tend to ruin molecular weight hand in hand with mechanical properties.

In our work we try to optimize composition of extraction solution, extraction time and temperature, and mixing patterns in order to reach highest yield of really pure (>99,5 % PHB in dry mass) polymer, while maintaining the use of chloroform at its necessary minimum.

We took 32 factorial design enhanced with two center

point repetitions for assessment of optimal composition

of extraction solution with respect to water:residual biomass ratio and chloroform:residual biomass ratio. Data was analyzed using standard response surface methodology. Experiments were carried in Biostat 2L fermentor using two 6 blades Ruston turbines. We found that the amount of chloroform is not limited from above, more chloroform added means higher yield and higher purity. The only limits are economical. In case of water addition there exist an optimum, at which residual biomass is not dispersed in such a way, that leads to unnecessary destruction of cell components with final result of phase inversion, i.e. hard-to-separate emulsion system.

With three different compositions (near the optimum find above) we tried to find optimal temperature of extraction in the range from 45 to 70 °C. We found that best results were obtained near boiling point of each extraction mixture. Use of higher temperatures leads to higher yields but also to massive decrease in purity.

Last influence, but really not least, is the type and number of impellers used, speed of agitation and time of extraction. When trying to shorten extraction time as possible it was found that simple Rushton turbines are inappropriate, leading to inadequate purity. Combination of turbines, with enough shear to break biomass clusters, and axial type impellers (e.g. hydrofoils), to create sufficient overall mixing pattern to prevent cavern formation in viscous mixture, is necessary to compromise between yield, purity and time of extraction.

Acknowledgement

This work was supported by the project “Materials Research Centre at FCH BUT – Sustainability and Development” No. LO1211 of the Ministry of Education, Youth and Sports of the Czech Republic and by the project FCH-S-18-5334.

152

12.3 20.3

24.8 28.3

37.3 38.0 40.0

44.4 45.1 46.5 48.1 49.8

53.7 55.0 56.4 56.5 56.8

60.3 60.3

68.2 72.8 73.1

77.0 78.3

90.1 92.5 94.2 95.1

0 20 40 60 80 100

LatviaKorea

EstoniaHungary

ChileTurkeySlovak…

IsraelNetherlands

ItalyGreeceFrance

LuxembourgCzech…

GermanyNorway

SloveniaOECD29

AustriaFinland

New ZealandSpain

DenmarkBelgiumCanadaSweden

United…PortugalAustralia

Iceland

Defined daily dose, per 1 000 people per day

2000 2015

129.6 104.2

Psychoactive pharmaceuticals in water

Petra Venská1, Martina Repková2, Milada Vávrová3

1 BUT Faculty of Chemistry, Czech Republic, Institute of Environmental Chemistry,

Purkyňova 464/118, 612 00 Brno, [email protected] 2 BUT Faculty of Chemistry, Czech Republic, Institute of Environmental Chemistry 3 BUT Faculty of Chemistry, Czech Republic, Institute of Environmental Chemistry

Keywords: water, wastewater, pharmaceuticals, antidepressants, activated sludge

There is growing concern of presence and potential

negative effects of pharmaceuticals even at trace concentration in the aquatic environment. Pharmaceutically active compounds and their metabolites enter the sewerage after disposal and excretion and are not efficiently removed by wastewater treatment plants [1,2].

This problem was first highlighted in the 1970s in the US but the important knowledge on environmental contamination by those compounds grew in the mid-90s with advances in analytical techniques [3].

Nowadays, a higher prevalence of psychiatric disorders leads to rising number of prescriptions for psychiatric pharmaceuticals, particularly antidepressants. Increased consumption is associated with higher environmental exposure and environmental risk [2].

The study deals with selected antidepressants, hypnotics and anxiety-treating drugs and their interaction with activated sludge in municipal sewage treatment plant. The possible negative influence of these compounds on microorganisms of the activated sludge is investigated as well as the potential to remove them from water with some advanced oxidation processes (AOPs). AOPs are highly effective methods to degrade miscellaneous pharmaceutically active compounds.

Figure 1: Antidepressant drugs consumption, 2000 and 2015 [7]

References

[1] LAJEUNESSE, A., S.A. SMYTH, K. BARCLAY, S. SAUVÉ a C. GAGNON. Distribution of antidepressant residues in wastewater and biosolids following different treatment processes by municipal wastewater treatment plants in Canada. Water research 46 (2012)

[2] SILVA, Liliana J.G., Celeste M. LINO, Leonor M. MEISEL a Angelina PENA. Selective serotonin re-uptake inhibitors (SSRIs) in the aquatic environment: An ecopharmacovigilance approach. Science of the Total Environment 437 (2012)

[3] SANTOS, Lúcia H.M.L.M., A.N. ARAÚJO, Adriano FACHINI, A. PENA, C. DELERUE-MATOS a M.C.B.S.M. MONTENEGRO. Ecotoxicological aspects related to the presence of pharmaceuticals in the aquatic environment. Journal of Hazardous Materials 175 (2010)

[4] OECDiLibrary health statistics, Health at a glance 2017. Available at: https://www.oecd-ilibrary.org/social-issues-migration-health/health-at-a-glance-2017/antidepressant-drugs-consumption-2000-and-2015-or-nearest-year_health_glance-2017-graph181-en

Acknowledgement This work was supported by the specific research project No. FCH-S-18-5331 from the Ministry of Education, Youth and


https://www.oecd-ilibrary.org/social-issues-migration-health/health-at-a-glance-2017/antidepressant-drugs-consumption-2000-and-2015-or-nearest-year_health_glance-2017-graph181-en



153

Analysis of Betaglucans in selected commercial products and higher

funghi with their possibility use in pharmaceutical industry.

Marie Vysoká1, 2, Dana Byrtusová 1, 2, H. Thra Phan2, P. Matoušková 1, 2, I. Márová 1, 2

1 Materials Research Centre, Faculty of Chemistry, Brno University of Technology, Purkyňova 464 /118,612 00

Brno, [email protected] 2 Institute of food science and biotrechnology, Faculty of Chemistry, Brno University of Technology,

Purkyňova 464 /118, 612 00 Brno

Keywords: β-Glucan, fungi, polyphenols, antioxidant activity, cytotoxicity

β-glucans are one of the most abundant forms of polysacharides found inside the cell wall of bacteria and fungus. All β-glucans are glucose polymers linked together by a 1→ 3 linear β-glycosidic chain core and they differ from each other by their length and branching structures. It possesses several physiological effects, including lowering plasma cholesterol level, control of postprandial glucose level, and immune modulation effects. The food industry can obtain the benefits of β-glucan for production of nutraceutical food products. In industrial conditions, it serves as an alternative to conventional food additives for the purpose of improved rheology. Characterization of β-glucan showed its potential as stabilizer, fat replacer, water binding agent, oil holding agent, and whipping agent. All of these characteristics make it suitable for use as an ingredient in food products.[1] Dietary β-glucans

also exert immunostimulatory and antitumor effects by activation of cells of the mucosal immune system via β-glucan receptors [2].

Overall group parameters such as polyphenols, flavonoids, antioxidant activity were determined by spectrophotometry. The amount of beta-glucans in the fungi and selected commercial products was measured after enzyme hydrolysis using commercial kit. The content and composition of fatty acids was measured by gas spectrometry. Using emission spectrometry (ICP/OES) the presence of heavy metals was analysed in fungal extracts. Cytotoxicity was tested by MTT test on human cell lines. In the last part the antimicrobial activity against Gram-positive bacterium Micrococcus luteus, Gram-negative Serratia marcescens and yeast Candida ģlabrata was tested.

References

[1] CHAN, Godfrey, Wing CHAN a Daniel SZE. The effects of β-glucan on human immune and cancer cells. Journal of Hematology & Oncology [online]. 2009, 2(1), 25- [cit. 2018-08-30]. DOI: 10.1186/1756-8722-2-25. ISSN 1756-8722. Dostupné z: http://jhoonline.biomedcentral.com/articles/10.1186/1756-8722-2-25

[2] NAKASHIMA, Ayaka, Koji YAMADA, Osamu IWATA, Ryota SUGIMOTO, Kohei ATSUJI, Taro OGAWA, Naoko ISHIBASHI-OHGO a Kengo SUZUKI. Β-Glucan in Foods and Its Physiological Functions. Journal of Nutritional Science and Vitaminology [online]. 2018, 64(1), 8-17 [cit. 2018-08-30]. DOI: 10.3177/jnsv.64.8. ISSN 0301-4800. Dostupné z: https://www.jstage.jst.go.jp/article/jnsv/64/1/64_8/_article

Acknowledgement This work was also supported by the project “Materials Research Centre at FCH BUT—Sustainability and Development”

no. LO1211 of the Ministry of Education, Youth and Sports of the Czech Republic.

http://jhoonline.biomedcentral.com/articles/10.1186/1756-8722-2-25

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