In situ X-ray photoelectron spectroscopy studies of interactions of evaporated metals with electroactive polyaniline films

X-ray photoelectron spectroscopy was employed for the in situ study of inte ractions between thermally evaporated Mg atoms and electroactive polyanilin e (PANI) films of various intrinsic oxidation states. Quantitative changes in the N1s core-level spectra and the Mg2p core-level spectra, as well as t he changes in surface chemical stoichiometry of these films throughout the Mg evaporation process were carefully monitored. Although the nitrogen site s appeared to be more attractive to the in-coming Mg atoms and the emeraldi ne base (EB) and nigraniline base (NA) films underwent an apparent decrease in intrinsic oxidation state ([=N]/[NH-] ratio) as a result of Mg evaporat ion, there is no direct interaction between the two species. On the other h and, the adsorbed oxygen from the bulk of the polymer film played a dominan t role in the interfacial interactions between the polymer and the metal. C haracterization of the delaminated indium-tin-oxide (ITO) and polymer surfa ces from EB film and its camphorsulfonic acid-doped counterpart cast on ITO substrates had also been carried out to evaluate the interaction of PANI w ith the high work function metal.