In situ X-ray photoelectron spectroscopy study of the interactions of evaporated magnesium with polyaniline films

X-ray photoelectron spectroscopy was employed for an in situ study of the interactions between thermally evaporated magnesium atoms and polyaniline films of various intrinsic oxidation states. Quantitative changes in the N 1s core-level spectra, the Mg 2p core-level spectra and the surface chemical stoichiometries of these films throughout the magnesium evaporation process were carefully monitored. Although the nitrogen sites appeared to be more attractive to the incoming magnesium atoms, and the emeraldine and nigraniline films underwent an apparent decrease in the intrinsic oxidation state ([N]/[NH] ratio) as a result of magnesium evaporation, there is no direct interaction between the two species. On the other hand, the adsorbed oxygen from the bulk of the polymer film played a dominant role in the interfacial interactions between the polymer and the metal.