XP-SPECTRA, SPUTTER EXPERIMENTS AND UV-VIS-REFLECTION SPECTRA OF POLYANILINE

Electrochemical formed polyaniline (PANI) films were studied both in situ and ex situ using XPS and UV/VIS spectroscopy. The samples studied ex situ were removed at given potentials and rinsed with water, with no changes in the oxidation state or concentration of counter ions. PANI-RED (0. 0 V (SHE) contained no anions and the XP-spectra showed an emeraldine-like structure and 0. 27 protonated nitrogen atoms/monomer. PANI-OX (1. 0 V (SHE) contained 0. 2 - 0. 3 counter ions/monomer throughout the film. UV/VIS spectroscopy shows a two step redox mechanism involving radical cations. The extended conjugation of PANI-OX was followed by both reflection spectroscopy and XP-shake-up peaks accompanying the photoionisation process. At potentials above 1. 0 V (SHE) overoxidation occurs with the removal of anions from the bulk film.