Polyaniline thin films – structural anisotropy study by use of synchrotron radiation surface diffraction

Polyaniline (PANI) protonated with camphorsulfonic acid (CSA) receives high interest but its molecular and crystalline structure is still unclear. We undertook detailed studies of thin films cast from m-cresol, dichlorometane and trifluoroacetic acid (TFAA) solutions. Such samples were subjected to diffraction measurements by use of the grazing incident beam technique, applying the z-axis diffractometer installed at the beamline BW2 at HASYLAB. We obtained very important information concerning an anisotropy of the crystalline reflections for all samples investigated. These results demonstrate the significance of the solvents on the structural ordering, and the observed anisotropy plays an important role in new modelling attempts for the crystalline structure.