Intrinsic redox states of polyaniline studied by high-resolution X-ray photoelectron spectroscopy

High-resolution X-ray photoelectron spectroscopic (XPS) measurements of the various intrinsic redox states of polyaniline (PANI), using a monochromati zed Al-K alpha source. were carried out. The presence of the imine, amine a nd positively charged nitrogen species corresponding to a particular intrin sic redox state and protonation level of the polymer was resolved quantitat ively and unambiguously. The result confirmed the peak assignments of forme r XPS core-level studies using the lower resolution non-monochromatized Mg- K alpha X-ray source. Thus, the high-resolution XPS using a monochromatized Al-K alpha X-ray source is a truly unique tool for the convenient and quan titative analysis of the various intrinsic redox states of PANI.