Recent progress in chemical modification of polyaniline

Polyaniline (PANI) has been the subject of considerable recent interest because of their unique electrical behavior, good environmental stability in doped and neutral states, ease of synthesis and wide applications in different fields. However, the main drawback of PANI is lack of solubility, which explains its limited processability due to a rigid backbone. Various procedures have been adapted to improve its processability. The major part of this review is a discussion of some of the methods employed for chemical modification of PANI, including doping via Acid-Base chemistry, sulfonation of PANI or copolymerization of aniline with sulfonated aniline derivatives, synthesis of PANI composites with processable polymers, copolymerization of aniline with substituted corresponding monomers, incorporation of polymeric chains or long and flexible alkyl chains in the PANI backbone, and enzymatic polymerization of aniline during the last decade.