Highly conducting polymers

Noda and Watanabe [42] reported a simple synthetic procedure for the free radical polymerization of vinyl monomers to give conducting polymer electrolyte films. Direct polymerization in the ionic liquid gives transparent, mechanically strong and highly conductive polymer electrolyte films. This was the first time that ambient-temperature ionic liquids had been used as a medium for free radical polymerization of vinyl monomers. The ionic liquids [EMIM][BF4] and [BP][Bp4] (BP is N-butylpyridinium) were used with equimolar amounts of suitable monomers, and polymerization was initiated by prolonged heating (12 hours at 80 °C) with benzoyl... 

W.H. Kim, A.J. Makinen, N. Nikolov, R. Shashidhar, H. Kim, and Z.H. Kafafi, Molecular organic light-emitting diodes using highly conducting polymers as anodes, Appl. Phys. Lett., 80 3844-3846 (2002). 

The penetration of thermoplastics and thermoplastic composites ranges from the totality of the considered parts, for example housings and casings where metals are nearly ousted, down to areas where there are only a few applications, such as for highly conductive polymers. 

Although these polymers are of interest none show outstanding conductivity or serve to illustrate any new point of theory. From the preparative point of view they represent a considerable effort toward the synthesis of new and more highly conducting polymers. 

Below are reported comparisons of the model with some experimental systems. We consider successively the behaviour of a highly conductive polymer like polyaniline in contact with solutions containing redox couples (Fe(CN6)3 /Fe(CN6)4 ) and the oxidation of hydroquinone (HQ) mediated by a moderately conductive polymer (pECBZ) film. 

J.-L. Bredas, Electronic structure of highly conducting polymers, in Handbook of Conducting Polymers, Vol. 2, T. A. Skotheim, ed., Marcel Dekker, New York, 1986. 

Poly diacetylenes. The polydiacetylenes (PDA s) are unique among highly conducting polymers discovered in the past years in that they can be obtained as highly perfect macroscopic single crystals.68 Upon solid-state polymerization of... 

Whether conjugated polymers are best described by a band model, such as the SSH model, or an exciton model, will depend crucially on the relative strengths of the electron-phonon and electron-electron interactions. After the discovery of highly conductive polymers, the band model was widely accepted and applied to the interpretation of experimental data. Gradually since that time, evidence that suggests that an exciton picture is more appropriate has been accumulating. Comparison of experimental results with the models described above has been used to estimate the relative importance of the two types of interaction. This will be discussed in the following sections. 

Paper presented at the Symposium on the Structure and Properties of Highly Conducting Polymers and Graphite, San Jose, California, March 29 - 30, 1979. 

Figure 8 Thickness dependence of total shielding efficiency (SET) of highly conducting polymers (A) stretched heavily iodine doped Tsukamoto polyacetylene, (B) camphor sulfonic acid doped polyaniline cast from m-cresol solvent, (C) PFg doped polypyrrole.

Many approaches have been developed for the production of ionic liquid-polymer composite membranes. For example, Doyle et al. [165] prepared RTILs/PFSA composite membranes by swelling the Nafion with ionic liquids. When 1-butyl, 3-methyl imidazolium trifluoromethane sulfonate was used as the ionic liquid, the ionic conductivity ofthe composite membrane exceeded 0.1 S cm at 180 °C. A comparison between the ionic liquid-swollen membrane and the liquid itself indicated substantial proton mobility in these composites. Fuller et al. [166] prepared ionic liquid-polymer gel electrolytes by blending hydrophilic RTILs into a poly(vinylidene fiuoridej-hexafluoropropylene copolymer [PVdF(HFP)] matrix. The gel electrolytes prepared with an ionic liquid PVdF(HFP) mass ratio of 2 1 exhibited ionic conductivities >10 Scm at room temperature, and >10 Scm at 100 °C. When Noda and Watanabe [167] investigated the in situ polymerization of vinyl monomers in the RTILs, they produced suitable vinyl monomers that provided transparent, mechanically strong and highly conductive polymer electrolyte films. As an example, a 2-hydroxyethyl methacrylate network polymer in which BPBF4 was dissolved exhibited an ionic conductivity of 10 S cm at 30 °C. 

Figure 8.1. Thickness dependence of total Shielding Efficiency (SE,) of highly conducting polymers measured at 6.5 GHz (from [23c]) sample A stretched heavily iodine doped Tsukamoto polyacetylene (dotted line is obtained by using calculation of Se, with approximated values of a absorption coefficient and n) sample B unstretched heavily iodine doped Tsukamoto polyacetylene sample C camphor sulphonic acid doped polyaniline in m-cresol solvent sample D PFe doped polypyrrole sample E TSO doped polypyrrole Inset comparison of (microwave conductivity), c, and tan 6, Reprinted from ref. 23c with permission. Copyright American Institute of Physics.

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