Approaches, polyaniline synthesis

Cholli AL, Thiyagarajan M, Kumar J et al (2005) Biocatalytic approaches for synthesis of conducting polyaniline nanoparticles. Pure Appl Chem 77 339-344... 

An extensive review of the synthesis of rc-conjugated polymers is presented using a tutorial approach to provide an introduction to the field intended for the undergraduate student and the experienced chemist alike. The many synthetic methodologies that have been used for the synthesis of conjugated polymers are outlined for each class of polymers with a focus on research from the 1990s. The effect of structure on electrical properties is detailed. Specific systems reviewed include the polyacetylenes, polyanilines, polypyrroles, polythiophenes, poly(arylene vinylenes), and polyphenylenes. 

S. K. Pillalamarri, F.D. Blum, and M.F. Bertino, Synthesis of polyaniline-gold nanocomposites using grafting from approach, Chem. Commun., 4584-4585 (2005). 

H. S. O. Chan, A. J. Neuendorf, S. C. Ng, P. M. L. Wong, D. J. Young, Synthesis of fully sulfonated polyaniline a novel approach using oxidative polymerisation under high pressure in the liquid phase, Chemical Communications 1998, 1327. 

A new class of water soluble polypyrrole has been prepared by selfdoping of the polymer. These self-doped polypyrroles can be prepared electrochemically or chemically, using various dopant anions covalently bound to the polymer backbone. The self-doped sulfonated polypyrrole is most commonly synthesized electrochemically in nonaqueous media. Electrochemical synthesis in aqueous media and chemical synthesis are not typically used, presumably due to issues with overoxidation. The postpolymerization modification of polypyrrole, in a manner similar to that used to form sulfonated polyaniline is rare [41]. The various synthetic approaches and properties of the polymer are discussed in the following sections. 

Electronic and photo-active polymers as a class of advanced materials have attracted a lot of interest during last two decades. Typically these materials are synthesized chemically or electrochemically under harsh conditions such as extremely low pH, toxic catalysts and byproducts. New enzymatic approaches have been developed for the synthesis of electro and photo active polymers such as polyanilines, polyazophenols, and polypyrene derivatives. These enzymatically synthesized materials show interesting optical and electronic properties. 

Most of our work has focused on polypyrrole, poly(3-methylthiophene), and polyaniline. These polymers can be synthesized via oxidative polymerization of the corresponding monomer. This can be accomplished either electrochemically [10,12,42] or by using a chemical oxidizing agent [43-45]. We have adapted both of these approaches so that they can be used to do template synthesis of conductive polymers within the pores of our nanoporous template membranes. The easiest way to do electrochemical template synthesis is to coat a metal film onto one surface of the membrane and then use this film to electrochemically synthesize the desired polymer within the pores of the membrane [12]. Chemical template synthesis can be accomplished by simply immersing the membrane into a solution of the desired monomer and its oxidizing agent [9,16,44]. 

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