AN ELECTROCHEMICAL STUDY OF POLY(PARA-PHENYLENE) IN CONDUCTIVE POLYMER BILAYER ELECTRODES

Polymerization and redox responses of bilayers consisting of poly(para phenylene) (PPP)\poly(3-octylthiophene) (POT) (signifying inner layer\ outer layer), POT\PPP, PPP\polypyrrole (PPy) and PPy\PPP have been stu died. The bilayers were made electrochemically on a Pt substrate. The bilayers obtained with PPP and POT were found to be compact and thinne r than the charges used for polymerization of both layers separately w ould predict. In the bilayer electrodes with PPP as the inner layer an d POT as the outer layer, the charge involved in the redox process (do ping-undoping) was in some combinations up to two times higher than th at of the same layers separately. In the bilayer combination PPP\PPy, the outer PPy layer could be charged although the PPP layer was still in its neutral state. Preparation of PPy\PPP bilayers was complicated by the high oxidation potential of biphenyl, resulting in simultaneous overoxidation of the inner PPy layer.