Structural study of chiral camphorsulfonic acid doped polyaniline

Abstract

Chiral camphorsulfonic acid [R-(-)-CSA] doped polyaniline (PANI) films have been studied using X-ray diffraction in combination with structure factor calculations. Scattering studies of dedoped films, which exhibit chiral activity, have also been performed. All samples formed partially crystalline films and displayed significant molecular anisotropy in the crystal unit cell with respect to film orientation. The crystalline features are interpreted using a lamellar molecular model in which parallel stacks of the PANI main chains alternate with layers of the CSA dopant. This organization could, in part, explain the high conductivities often recorded in CSA-doped films. No obvious features within crystalline regions of the doped or dedoped films were observed which correlate with the chiral recognition seen in dedoped films.