The Chemical and Physical Properties of Pyrrole-Based Conducting Polymers: The Characterization of As-Grown Films by X-Ray Photoemission Spectroscopy.

Abstract : XPS techniques have been used to characterize electrically conducting films of polypyrrole and polybithiophenes grown electrochemically. These techniques have yielded information not only on the nature of the polymeric cation and its counter anion but also on the structural disorder in these polymers. In particular the N1s spectra have revealed a non-uniformity in the distribution of the anions relative to the nitrogen atoms and the C1s spectra clearly show that approximately 1/3 of the pyrrole rings are different from the rest. Significant improvement in the structural order is achieved by blocking the beta sites on the pyrrole ring with methyl groups to ensure a completely bonded polymer. Similar experiments on polybithiophene polymers show that this polymer is considerably more ordered than polypyrrole.