Electrochemical Science and Technology of Polymers-1

Polymers are normally thought of as insulators. In the last few years, however, a rapidly advancing and changing field has developed which exploits the ability of certain polymers to conduct charge, in some cases electronically and in others by means of ions. Certain electrochemical processes of major present-day industrial importance depend on the presence of polymeric materials for their efficient operation. The chlor-alkali industry is a prime example. Exciting new power sources, in which polymers replace conventional electrodes and/or electrolytes, are being intensively developed. Re­ markable advances in the understanding of electrochemical processes and the development of a range of sophisticated sensors and other devices have been made possible by the use of polymer-coated electrodes. The impact of polymers on the electrochemical field is still in its initial growth phase. The results of a rapidly escalating volume of industrial and academic research are being applied in many contexts, especially in the information technology field. In certain areas, the use of polymers is only just beginning to show its impact. In the next year or so, the use of polymerised Langmuir-Blodgett films as a substitute for conventional E-beam resists in electronics can be anticipated. By the end of the decade, polymerised mono- and multi-layers may be incorporated in very large-scale integrated circuits.

1 Ionic and Electronic Transport.- 1 Introduction.- 2 Electrochemical reactors.- 3 The electrode/electrolyte interphase.- 3.1 Reversible electrodes and the standard electrode potential.- 3.2 Dependence of electromotive force on concentration.- 3.3 Dependence of electromotive force on temperature.- 3.4 Overpotential.- 3.5 Summary.- 4 Solid state cells.- 4.1 Mechanisms of ionic conduction in the solid state.- 4.2 Polymeric electrolytes.- 5 Measurement of conductivity.- 5.1 The complex plane representation.- 5.2 Electronic conductivity.- References.- 2 Polymer Structure and Conductivity.- 1 Introduction.- 2 Macromolecular structure.- 3 Amorphous polymers.- 3.1 Flexibility and flow.- 3.2 The glass transition.- 4 Polymer crystallinity.- 4.1 Crystallisability.- 4.2 Crystallinity.- 4.3 Crystallisation.- 5 Spherulites.- 6 Implications.- 7 Conclusions.- References.- 3 Ion Conducting Polymers.- 1 Introduction.- 2 The chemistry and structures of polymer complexes and solutions.- 3 The kinetics of ion transport.- 3.1 Free volume theory.- 3.2 Application to ion conduction.- 3.3 Conclusions regarding kinetics.- 4 Electrical measurement techniques.- 5 Current research directions.- References.- 4 Organic Polymers as Electroactive Materials.- 1 Introduction.- 2 p- and n-doping of polyacetylene.- 3 Basic concepts of electrochemistry.- 4 Polyacetylene as an electrode material.- 5 The polyacetylene cathode.- 5.1 Use of p-doped (oxidized) polyacetylene.- 5.2 Use of n-doped (reduced) polyacetylene.- 6 The polyacetylene anode.- 7 Batteries employing polyacetylene anodes and cathodes.- 8 Batteries using other conducting polymers.- 9 Present status of batteries employing polymer electrodes.- 10 Conclusions.- Acknowledgements.- References.- 5 Polymer Modified Electrodes: Preparation and Characterisation.- 1 Introduction.- 2 Preparation.- 2.1 Pre-formed polymers.- 2.2 Polymers formed/coated simultaneously.- 3 Electrochemical characterisation.- 3.1 Objectives and limitations.- 3.2 Simple models of polymer films on electrodes and general approach.- 3.3 Thermodynamic parameters.- 3.4 Kinetic parameters.- 4 Spectroscopic and other non-electrochemical characterisation techniques.- 4.1 Macroscopic observations and properties.- 4.2 ‘Monomer’/redox centre observation.- 4.3 Sub-molecular units.- 4.4 Atoms.- 4.5 Other techniques.- 5 Conclusions.- References.- 6 Reactions and Applications of Polymer Modified Electrodes.- 1 Introduction.- 2 Theoretical treatments of mediated charge transfer.- 2.1 Basic models and concepts.- 2.2 Analysis of mediated charge transfer.- 2.3 Experimental tests of the analysis.- 2.4 Other mechanistic studies.- 2.5 Summary.- 3 Applications.- 3.1 Introduction.- 3.2 Electrochemical synthesis.- 3.3 Sensors.- 3.4 Corrosion protection of metals.- 3.5 Semiconductor electrochemistry.- 3.6 Photogalvanic effects.- 3.7 Immobilisation of particulates.- 3.8 Display devices.- 3.9 Electronic and electrochemical devices.- 4 Conclusions.- References.- 7 Perfluorinated Ionomer Membranes for Use in the Production of Chlorine and Caustic Soda.- 1 Introduction.- 1.1 Historical perspective to membrane cell technology.- 1.2 Current commercial chlorine technology.- 2.Perfluorinated sulphonate ionomers.- 2.1 Synthesis of perfluorosulphonate polymers.- 2.2 Commercial exploitation of perfluorosulphonate ionomers.- 2.3 Physical properties of perfluorosulphonate ionomers.- 3 Perfluorinated carboxylate ionomers.- 3.1 Synthesis and polymerisation of perfluorinated carboxylate monomers.- 3.2 Fabrication of perfluorinated membranes.- 3.3 Surface topography of perfluorinated ionomers.- 3.4 Physical properties of perfluorocarboxylate ionomers.- 4 Mixed perfluorinated sulphonate/carboxylate ionomer membranes.- 5 Structure/transport relationships in perfluorinated ionomer membranes.- 5.1 Basic structural features of perfluorinated ionomers.- 5.2 Experimental correlations between polymer structure and transport properties.- 5.3 Quantitative relationships involving ionic transport.- 6 Present and future trends in perfluorinated ionomer membrane cell technology.- Acknowledgement.- References.