Bulk–surface nanostructure and defects in polyaniline films and fibres

Polyaniline films and fibres were prepared by different ways using meta-cresol and camphor sulfuric acid. Their microstructures were studied by scanning electron microscopy and compared to those of films prepared using the NMP route and a usual emeraldine chloride salt powder. Raman scattering under various exciting conditions was used to determine the structure of the different polymorphs (Types I and II), which was correlated with the process. Structure #I is observed at the surface preferentially. Partial surface de-protonation and formation of quinoic segments with special geometry are evidenced.