Influence of doping on the structure and electrical properties of poly(aniline)

Poly(aniline) has been synthesized electrochemically from an aqueous soluti on of aniline and perchloric acid at different constant current densities o f 0.30, 0.60, 0.90, 1.20 and 1.50 mA cm(-1) in order to prepare the polymer s at different doped states. The doped polymers thus synthesized are found to exhibit excellent crystallinity and higher conductivity than those of de doped one. Analysis of the studied samples by UV-vis spectroscopy also indi cates differences in the structure of doped and dedoped polymers. Effects o f ambient atmosphere and heating on the doped polymers have also been exami ned based on the measurements of X-ray diffraction pattern, d.c. conductivi ty together with the optical studies. An irreversible deactivation of the s tructure and electrical properties has been observed upon heating and agein g the polymers in air.