Conducting conjugated polymers

Because of the aqueous solubiUty of polyelectrolyte precursor polymers, another method of polymer blend formation is possible. The precursor polymer is co-dissolved with a water-soluble matrix polymer, and films of the blend are cast. With heating, the fully conjugated conducting polymer is generated to form the composite film. This technique has been used for poly(arylene vinylenes) with a variety of water-soluble matrix polymers, including polyacrjiamide, poly(ethylene oxide), polyvinylpyrroHdinone, methylceUulose, and hydroxypropylceUulose (139—141). These blends generally exhibit phase-separated morphologies. 

Conjugated Conducting Polymers (Ed. H.G. Kiess), Springer, Berlin Germany, and New York, USA, 1992. 

H. Kiess (Ed.), Conjugated Conducting Polymers, Springer-Verlag, Berlin, 1992. 

Furukawa Y (1996) Electronic absorption and vibrational spectroscopies of conjugated conducting polymers. J Phys Chem 100 15644... 

Conjugated conducting polymers consist of a backbone of resonance-stabilized aromatic molecules. Most frequently, the charged and typically planar oxidized form possesses a delocalized -electron band structure and is doped with counteranions (p-doping). The band gap (defined as the onset of the tt-tt transition) between the valence band and the conduction band is considered responsible for the intrinsic optical properties. Investigations of the mechanism have revealed that the charge transport is based on the formation of radical cations delocalized over several monomer units, called polarons [27]. 

D. Baeriswyl, D.K. Campbell and S. Mazumdar, in Conjugated Conducting Polymers, edited by H. Kiess (Springer-Verlag, Heidelberg, 1992). pp7-133. 

D. Baeriswyl, D. K. Campbell and S. Mazumdar, in Conjugated Conducting Polymers, H. G. Kiess (Ed.), (Springer, Berlin 1992) Y. Anusooya, B. Srinivasan and S. Ramasesha, in Strongly Correlated Electron Systems in Chemistry, S. Ramasesha and D. D. Sarma (Eds.), (Naxosa Publishing House, New Delhi, 1996) p. 67. 

Baeriswvl D, Campbell DK and Mazumdar S, in Keiss HG (Eds), "Conjugated Conducting Polymers", Springer Verlag, Berlin, p 7,1992. 

W. Rehwald and H. G. Kiess, in Conjugated Conducting Polymers, Springer Series in Solid-State Sciences, Vol. 102 (H. Kiess, ed.), Springer-Verlag, Berlin, 1992, p. 135. 

In the case of conjugated conducting polymers, which were previously mentioned, the ET theory applies since the conductivity is not a simple band type conductivity but, depending on the doping level, merely an intrachain and/or interchain motion of charged soliton-like or polaron-like defects. We can sketch this motion as indicated in Fig. 36.26. 

Conjugated conducting polymers have been found in some cases to present by themselves an intrinsic electrocatalytic activity. Among the few examples, polypyrrole has been shown to be an interesting catalyst for the quinone-hydroquinone redox system [34,35] or for the electro-reduction of dioxygen [36]. 

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