NEW FINDINGS ON POLYPYRROLE CHEMICAL-STRUCTURE BY XPS COUPLED TO CHEMICAL DERIVATIZATION LABELING

Polypyrrole electrosynthesised from aqueous solutions has been investi gated by XPS, both in the conducting (PPY) and in the so-called overox idised (PPYox) state. An accurate analysis of high resolution spectra, including cross-checking between the independent fittings of differen t though related signals (e.g. Cls and Ols), is presented, enlightenin g novel findings on polypyrrole structure. In particular, it suggested , for the first time, that overoxidation breaks polymer chains, produc ing new oxygen function on alpha-C (mainly C=O). The application of a new chemical derivatization (CD) method to the labelling of this key f unctional group (C=O) would confirm this feature.