SLOW RELAXATION IN CONDUCTING POLYMERS - INFLUENCE OF THE WAIT POTENTIAL

It has been shown that the kinetics of the electrochemical doping of a conducting polymer depends on the time spent in the neutral state, t( w), In particular, for increasing t(w), the oxidation peak current upo n potential scanning is higher and higher, and is shifted according to a logarithmic law : V(r) = V(o) + a log t(w). Further investigations of this effect are presented. In particular, the influence of the pote ntial imposed during the wait time V(w), is investigated in the case o f a polyaniline film in acidic aqueous solution. It is shown that the relaxation effect can be observed also at potentials corresponding to a significant doping level, the film being conducting. Charging of the film during waiting in this range of potential is very slow (logarith mic law). It is predicted from the data that reaching equilibrium woul d require about one year.