CHAPTER 12: Polyanilines

Polyanilines are highly conjugated polymers consisting of alternating amine/imine and benzenoid/quinoid sequences that are best known for their versatile redox chemistry and robust electrical conductivity upon protonic doping. Polyanilines can be oxidatively synthesized from aniline and aniline derivatives through chemical and electrochemical routes, each possessing distinct advantages. The electrically conductive form of polyanilines preferentially formed during oxidative synthesis exhibit extensive conjugation and electron delocalization, which severely limit their solubilities in common solvents. Attempts to increase solubility have resulted in polyanilines that are synthesized on a variety of templates. While dispersible, these template polyanilines exhibit substantially reduced electrical conductivities. Much research on polyanilines has thus focused on improving their processability while maintaining their functionality. This chapter addresses experimental details regarding the polymerization of many aniline and aniline derivatives through chemical, electrochemical, and template synthesis procedures, and additionally, highlights examples of postprocessing secondary doping procedures that dramatically enhance the electrical, electrochemical, and optical properties of polyanilines.