COMPARISON OF CHEMICALLY AND ELECTROCHEMICALLY PREPARED POLYANILINE FILMS .2. OPTICAL-PROPERTIES

Relaxation phenomena in thin polyaniline films synthesized chemically and electrochemically are investigated by UV-vis and IR spectroscopy. It is shown that the relaxation process carried out from the electroch emically oxidized or electrochemically reduced states of the polyanili ne always proceeds toward the emeraldine state. The relaxation process in acid is governed by disproportionation and formation of semiquinon e radicals. The changes in the population density of the polaronic sta tes within the polaronic band allows determination of the change in th e oxidation state and consequently the change in the position of the F ermi energy level. The formation of polaronic states is ascertained by diffusion of ions from or into the polyaniline matrix in solution and within the polymer in air.