XPS study of polyaniline during reduction role of the waiting time

It is shown in this paper that the amount of counter ion (dopant) decreases during the polarization in the reduced state of polyaniline, namely, leucoemeraldine. This effect is attributed to a change of the double-layer structure. Indeed, since the polarization is negative versus the potential of zero charge (PZC) and the electrode is negative, the counter ion is repelled from the double-layer region inside the polymer film.