Caracteriza？？o por Espectroscopia Fotoelectrónica de Raios X (XPS) de filmes de polipirrole em cobre

polypyrrole films were electrochemically deposited onto copper substrates from an aqueous salycilate solution. the potential transients registered during the galvanostatic films growth, in particular the absence of a period related with the metal dissolution, revealed the effective polypyrrole deposition. the similarity between the results obtained on platinum and on copper allows concluding that the electropolymerization process is not strongly influenced by the substrate nature. the x-ray photoelectron spectroscopy characterization of the ppy films, confirmed the deposition of a uniform polymeric layer. a detailed analysis of the xps results, for the different interfaces, revealed that the loss of polymer adherence after being submitted to a constant potential lower than -0.5 v vs. sce, is a result of the complete removal of the formed intermediary passive layer.