Influence of the nature of substituent on the charge mechanisms in substituted polyanilines (SPANI, POMA) studied by Raman and optical spectroscopies

The structural and electronic characteristics of substituted polyanilines (PANI) were studied in order to understand why substituents on the aniline ring enhance, or not, the protection of iron against corrosion with respect to the protection given by an unsubstituted polyaniline layer. The substituent can modify the polaronic nature (localized or delocalized polaron, bipolaron) of polyaniline. “Electron donor” or “electron acceptor” substituents were therefore compared without leading to a definitive conclusion.