Formation and electronic conductivity of polyaniline

Potentiostatic measurements of polyaniline (PANI) formation show the growth of a metallic conducting phase, probably growing after instantaneous nucleation by a semisphere mechanism. The double layer capacity proves the formation of a metallic phase at first, but in a later stage the surface is covered by any dielectric reaction product forming an interface of a few nm thickness. Various measurements of electron transfer reactions show the very good conductivity of the PANI film within a potential range of 0 to 1 V. A large nucleation overvoltage hinders the cathodic metal deposition. Oxidation at higher potentials causes an overoxidation with the formation of an insulating film.