It is shown for the first time that the redox switching of polyaniline
(PANI) under voltammetric conditions is accompanied by the following
processes: oxidation of PANI by atmospheric oxygen in the range of low
potentials (E < 0.2 V); reduction with addition of aniline (post-poly
merization) at E > 0.2(5) V, which in the range 0.2(5) < E < 0.5 V com
pensates entirely for the oxidation over the timescale of the cyclic v
oltammogram. These processes determine: (a) the existence of the emera
ldine (conducting) state in a potential window (instead of at a define
d potential); (b) the fundamental asymmetry in the redox behaviour of
PANI; (c) the difference in the rates of the oxidation and reduction t
ransients and (d) the dependence of the electrochemical activity of PA
NI on the pH of the medium.