Conductive polymers processing

Aldissi, M. Inherently Conducting Polymers— Processing, Fabrication, Applications, Limitations Noyes Data Corporation Park Ridge, NJ, 1989. 

Abdou MSA, Orfino FP, Son S, Holdcroft S (1997) Interaction of oxygen with conjugated polymers charge transfer complex formation with poly(3-alkylthiophenes). J Am Chem Soc 119 4518-4524 Aldiss M (1989) Inherently conducting polymers processing, fabrication, applications, hmitations. Noyes Data Corporation, Park Ridge... 

FIGURE 30.6 Principle of conductive polymer process (a) conditioning (6) monomer created on the surface (c) oxidant reduces monomer to polymer yielding highly conductive surface (d) further improved conductive surface. 

Aldissi, M., "Stability and Stabilization of Pristine and Doped Polymers", Chapter VII (p. 52) in/n/terenr/y Conducting Polymers Processing, Fabrication, Applications, Limitations, Noyes Data Corporation, New Jersey, USA (1989). 

Until a few years ago it was not possible to realize high capacitance and low ESR solid electrolyte capacitors with conductive polymer dispersions. Therefore, today, in situ polymerization is mainly used for conductive polymer processing in electrolytic capacitors. In situ polymerization can either be conducted by electrolytic oxidation or by chemical oxidation. 

The thermal conductivity of polymeric fluids is very low and hence the main heat transport mechanism in polymer processing flows is convection (i.e. corresponds to very high Peclet numbers the Peclet number is defined as pcUUk which represents the ratio of convective to conductive energy transport). As emphasized before, numerical simulation of convection-dominated transport phenomena by the standard Galerkin method in a fixed (i.e. Eulerian) framework gives unstable and oscillatory results and cannot be used. 

Reversible oxidation and reduction of polymers is commonly used to increase conductivity in these systems. Ions from the electrolyte are usually incorporated into the polymer as part of this process (see Electrically conducting polymers). 

The development of polythiophenes since the early 1980s has been extensive. Processible conducting polymers are available and monomer derivathation has extended the range of electronic and electrochemical properties associated with such materials. Problem areas include the need for improved conductivity by monomer manipulation, involving more extensive research using stmcture—activity relationships, and improved synthetic methods for monomers and polymers alike, which are needed to bring the attractive properties of polythiophenes to fmition on the commercial scale. 

Practical appHcations have been reported for PVP/ceUulosics (108,119,120) and PVP/polysulfones (121,122) in membrane separation technology, eg, in the manufacture of dialysis membranes. Electrically conductive polymers of polyaruline are rendered more soluble and hence easier to process by complexation with PVP (123). Addition of small amounts of PVP to nylon 66 and 610 causes significant morphological changes, resulting in fewer but more regular spherulites (124). 

Common conductive polymers are poly acetylene, polyphenylene, poly-(phenylene sulfide), polypyrrole, and polyvinylcarba2ole (123) (see Electrically conductive polymers). A static-dissipative polymer based on a polyether copolymer has been aimounced (124). In general, electroconductive polymers have proven to be expensive and difficult to process. In most cases they are blended with another polymer to improve the processibiUty. Conductive polymers have met with limited commercial success. 

The rapid development of many processible conducting polymers that can now be obtained as films, fibers, and molded shapes, suggests that they will be quite useful in a number of appHcations. One of the concerns presendy being addressed is the stabiUty of the conductive polymers during these specific uses. 

The science and technology of conducting polymers are inherently interdisciplinary they fall at the intersection of three established disciplines chemistry, physics and engineering hence the name for this volume. These macromolccular materials are synthesized by the methods of organic chemistry. Their electronic structure and electronic properties fall within the domain of condensed matter physics. Efficient processing of conjugated polymer materials into useful forms and the fabrication of electronic and opto-electronic devices require input from engineering i. e. materials science (more specifically, polymer science) and device physics. 

Formation Processes and Properties of Conducting Polymer Composites... 

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