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 electrochemically oxidized or electrochemically reduced states of the polyaniline always proceeds toward the emeraldine state. The relaxation process in acid is governed by disproportionation and formation of semiquinone radicals. The changes in the population density of the polaronic states within the polaronic band allows determination of the change in the oxidation state and consequently the change in the position of the Fermi 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.