X-ray scattering study of CSA protonated polyaniline films and powders

An X-ray scattering study was carried out on camphorsulfonic acid-protonated emeraldine base samples in water, m-cresol and in their mixtures. The X-ray profiles strongly depend on the protonation conditions and on the molecular weight of the emeraldine base (EB). The protonation of the EB in solution in m-cresol enables a better crystallization than inside the EB powder suspended in aqueous acidic solution. X-ray profiles evolved when protonated EB m-cresol-free samples were exposed to m-cresol vapors, indicating that m-cresol enhances the crystallinity and the structural order. All different X-ray profiles of the films could be indexed with a sole orthorhombic cell with a = 21.5 إ, b = (2x) 3.5 إ and c = 18.6 إ.