IMPEDANCE ANALYSIS OF POLY(O-PHENYLENEDIAMINE) ELECTRODES

Electrochemical impedance spectra obtained for poly(o-phenylenediamine ) films in contact with solutions of different compositions were analy zed on the basis of selected models. The Kramers-Kronig transformation has been used for validation of the impedance data. Complex non-linea r least squares fitting and computer simulation have been used to deri ve reliable quantities characterising the electrochemical behaviour of these systems. It has been shown that the charge transport diffusion coefficient strongly decreases with increasing potentials. The potenti al dependence of low-frequency capacitance attests to strong interacti ons within the film that depends upon the nature of anions. The partic ipation of protons in the redox reactions has also been demonstrated. (C) 1997 Elsevier Science S.A.