Effect of β-cyclodextrin on the solid-state synthesized polyaniline doped with hydrochloric acid

Polyaniline (PANI) salts doped with hydrochloric acid were prepared by using solid-state polymerization in the presence of beta-cyclodextrin (beta-CD) at room temperature. The fourier transform infrared (FTIR) spectra, ultraviolet-visible absorption spectra, X-ray diffraction patterns were used to characterize the molecular structures of these polymers. Cyclic voltammetry study and conductivity measurements were done to investigate their electrochemical behaviors. The morphology of polymers was studied by the scanning electron microscopy and transmission electron microscopy. The results showed that PANI salts prepared in the presence of beta-CD had different physicochemical characteristics compared with PANI salt prepared in the absence of beta-CD. When the molar ratio of aniline to beta-CD was 80/20, the obtained PANI salt displayed higher crystallinity, conductivity and electrochemical properties. However, these properties were opposite on condition that the molar ratio of aniline to beta-CD was 50/50. The results also revealed that the morphology of PANI salt was affected by beta-CD, especially at aniline/beta-CD molar ratio in the feed of 50/50, in which PANI salt displayed rodlike structure morphology with a diameter of near 80-100 nm. (C) 2007 Wiley Periodicals, Inc.