Ion size and size memory effects with electropolymerized polyaniline

The influence of the ion size of anions (chloride, perchlorate, sulphate and p-toluene sulphonate (PTSA)) present during electropolymerization and reversible electrochemical doping/dedoping of polyaniline has been studied with cyclic voltammetry, in situ UV–VIS spectroelectrochemistry and in situ conductivity measurements. The results were compared with respect to possible correlations between optical and electronic properties and the identity of the anion being present during formation and doping/dedoping of the polymer. Results indicate, that a significant “size memory effect” based on anion size or a related property could not be deduced from experimental results within the range of investigated anions.