A study into electrochemical slow relaxation of polyaniline

The electrochemical slow relaxation (SR) has been studied for poly(styrene sulfonate)-doped polyaniline (PANI), and a copolymer of aniline and metanilic acid, electrodeposited onto platinum electrode. For both PANI derivatives, well-defined SR effect has been observed. The dependence of SR on polymer film thickness and waiting potential was studied. An inverse sigmoidal dependence of SR on waiting potential has been found. A weak or no SR was found by extending the waiting potential over 0.05 V versus Ag/AgCl. Based on the peculiarities observed, it has been concluded that SR is hardly concerned with dopant anion movement during redox transformations of PANI, and a model for the mechanism of SR effect has been proposed.