ELECTROCHEMICAL STUDY ON THE POLYPYRROLE-POLYANILINE BILAYERS

Cyclic voltammetric and ac impedance studies on polypyrrole(PPy)-polya niline(PANI) bilayer films have been carried out in aqueous medium. Th e bilayers were prepared by electrochemical polymerization of the corr esponding monomers at a platinum electrode in 1M HCI solution. Cyclic voltammograms of the bilayers show additive properties of the individu al polymers. The ac impedance studies of the bilayers show that when P Py is the outer layer oxidation of the inner PANI layer is mediated. T he largest difference between the impedance plots of the PPy/PANI and PANI/PPy bilayers is observed at 0 V where PPy already is in its condu cting state but PANI first starts to become oxidized.