Contents
Author contact details ix
Preface xi
Part I Theoretical considerations 1
1 Fundamentals of electrochemistry 3
P. WESTBROEK
1.1 Introduction 3
1.2 What is an electrochemical reaction? 4
1.3 Conventions for presentation of electrochemical data 8
1.4 Classification of electrochemical methods 9
1.5 Two-electrode setup 10
1.6 Three-electrode setup 13
1.7 Charge-transfer and transport phenomena 25
1.8 References 34
2 Electrochemical methods 37
P. WESTBROEK
2.1 Introduction 37
2.2 Potentiometry 37
2.3 Cyclic voltammetry 43
2.4 Impedance of electrochemical systems 50
2.5 Chronoamperometry 60
2.6 Other voltammetric methods 61
2.7 References 67
Part II Electrochemistry in textile finishing 71
3 Probes for pH measurement and simultaneous cellulose removal and bleaching of textiles with enzymes 73
P. WESTBROEK AND P. KIEKENS
3.1 Introduction 73
3.2 Ion-selective electrodes 73
3.3 Glass-membrane electrodes 75
3.4 Simultaneous cellulose removal and bleaching with enzymes 81
3.5 References 90
4 Electrochemical behaviour of hydrogen peroxide oxidation: kinetics and mechanisms 92
P. WESTBROEK AND P. KIEKENS
4.1 Introduction 92
4.2 Use of hydrogen peroxide in textile-bleaching processes 93
4.3 Determination methods of hydrogen peroxide 96
4.4 Voltammetric behaviour 97
4.5 Detection of high hydrogen peroxide concentrations with amperometric method 98
4.6 Theoretical I–E relationship for mechanism 1 112
4.7 Theoretical I–E relationship for mechanism 2 120
4.8 The pseudo-limiting-current 123
4.9 Combination of rate equations of both mechanisms 126
4.10 References 130
5 Amperometric detection of hydrogen peroxide in bleaching and washing processes 133
P. WESTBROEK AND P. KIEKENS
5.1 Introduction 133
5.2 Influence of temperature 133
5.3 Behaviour of the sensor electrode at the laboratory scale 135
5.4 Behaviour of the sensor in an industrial environment 144
5.5 Expanding the sensor system for processes occurring at pH<10.5 152
5.6 References 160
6 Simultaneous detection of indigo and sodium dithionite for control of dyeing processes 161
P. WESTBROEK AND P. KIEKENS
6.1 Introduction 161
6.2 Basic electrochemical reactions of dithionite and sulphite 162
6.3 Kinetic limitations in oxidation of dithionite and sulphite 168
6.4 Mechanism of the charge-transfer kinetics of dithionite oxidation 174
6.5 Detection of sodium dithionite 183
6.6 Detection of indigo 184
6.7 Simultaneous detection of sodium dithionite, sulphite and indigo at a wall-jet electrode 185
6.8 References 196
7 Advantages of electrocatalytic reactions in textile applications: example – electrocatalytic oxidation of sodium dithionite at a phthalocyanine and porphyrin
cobalt(II)-modified gold electrode 198
P. WESTBROEK
7.1 Introduction 198
7.2 Electrodeposition of Co(II)TSPc at gold electrodes 199
7.3 Analysis of the data 204
7.4 Electrocatalysis with modified gold electrodes towards sodium dithionite 206
7.5 References 211
Part III Textile electrodes 213
8 Intelligent/smart materials and textiles: an overview 215
G. PRINIOTAKIS
8.1 Introduction 215
8.2 Smart materials 216
8.3 Intelligent/smart textiles 221
8.4 Electrotextiles 227
8.5 Intelligent clothing 236
8.6 References 239
9 Characterisation of electrochemical cell for textile electrode studies and quality control 244
G. PRINIOTAKIS, P. WESTBROEK AND P. KIEKENS
9.1 Introduction 244
9.2 Characterisation of an electrochemical cell 244
9.3 Method for quality control of textile electrodes 254
9.4 Conclusion 273
9.5 References 273
10 Electroconductive textile electrodes for detection and analysis of sweat and urine 274
P. WESTBROEK, G. PRINIOTAKIS AND P. KIEKENS
10.1 Introduction 274
10.2 Description of the cell configuration 276
10.3 Conditions for using yarn electrodes 277
10.4 Cell configuration with immobilised electrolyte solution 280
10.5 Experiments with artificial sweat and under real-time conditions 280
10.6 References 284
Part IV Modified fibres and their applications 285
11 Chemical metallisation and galvanisation as a method for development of electroconductive polyacrylonitrile fibres 287
P. WESTBROEK AND P. KIEKENS
11.1 Introduction 287
11.2 Optimisation of process parameters in polyacrylonitrile production for metallisation with nickel 288
11.3 Optimisation of electroconductive PAN-fibre production 295
11.4 References 307
12 Textile fibres used as electrode materials in analytical applications 308
P. WESTBROEK
12.1 Introduction 308
12.2 A platinum-fibre electrode for detection of Cu(II) and Cu(I) in non-aqueous solution 308
12.3 Determination of SO2 reactions as a function of pH and its detection at modified carbon-fibre electrodes 317
12.4 Gold-fibre textile electrodes obtained through chemical modification for the detection of Ce(IV) during polymerisation reactions of bio-polymers 327
12.5 References 336
Index 341
Preface
This book is the result of 13 years of research by the authors in the field of analytical electrochemistry with applications in textiles. However, without the support of many people, we would not have been able to bring this book, and the research explained in it, to a good conclusion. We would therefore like to thank all the people listed below for their help and would ask for forgiveness if anyone is not mentioned in this list.
First of all, we would like to thank our families for all their support and encouragement in our work.Without them, our jobs would be much more difficult.
We thank also the people from Ghent University, Department of Analytical Chemistry, Belgium: Professor Eduard Temmerman, Professor Harry Thun, Joost, Ine, Jan, Karolien, Filip, Fabien, Bart, Severine, Danjiella, Kathleen, Brigitte, Françoise and Michel. From Ghent University, Department of Textiles, Belgium, we should express our gratitude to Professor Lieva Van Langenhove, Emmanuel, Jean, Karen, John, Kyriaki, Vaggelis, Mojca, Jan and Lieve. Special thanks also to Judith for the translation of Chapters 4 and 5. Finally, we would like to thank the researchers from Rhodes University, Department of Chemistry, South Africa for their valuable input through bilateral cooperation: Professor Tebello Nyokong, Joshua, Kenneth, Mozes, Nchinda, Mamothibe, Natasha, Suzanne, Pulane, Sibongiseni, Andre and Rubin.
Finally, we would also like to thank the official bodies for providing us with the necessary financial support to execute our research projects: Ghent University (Belgium), Rhodes University (South Africa), Institute for Promotion of Scientific Research and Technology in Flemish Industry (IWT, Belgium), Vlaams Wetenschappelijke Stichting (VWS, Belgium), European Union (Europe) and the National Research Foundation (NRF, South Africa).
The book is divided into four parts. In the first part, an overview is given of the theory of electrochemistry as well as some practical considerations. The second part covers the development of sensors for the optimisation and automation of textile-finishing processes. In Part III, after providing an overview of intelligent, or smart, materials, a brief fundamental study is given of textile electrodes that are used in a wide variety of applications but, for reasons of a lack of reproducibility and low electrode stability, are not yet known within the industry.Tentative answers to the questions raised are formulated, and a quality-control method is developed and provided. Finally, the fourth part of the book deals with the functionalisation of fibres through chemical/electrochemical modification, and some applications are given for this type of textile-related electrode.