Improvement of reversible photoelectrochromic reaction of polyaniline in polyelectrolyte composite film with the dichloroethane solution system

Photorewritable conducting polyaniline (PAn) image was successfully obtaine d by the photopolyrmerization of aniline derivatives with Flemion polyelect rolyte composite film containing Ru(bpy)(3)(2+) and TiO2. The image can be erased and regenerated by consecutive photoreduction and photooxidation via photoinduced electron transfer for TiO2 and Ru(bpy)(3)(2+) in the polyelec trolyte composite film, respectively. These photoinduced reactions were con siderably affected by the deaeration condition for the reaction solution. W hen the photooxidation and photoreduction were carried out in the reaction solution deaerated with O-2 and N-2, respectively, good reversibility was o btained on the present system. However, the decomposition of the PAn was ob served by excessive photooxidation in the acidic aqueous solution due to th e hydrolysis of the PAn. In order to prevent the PAn decomposition, photore dox reaction of the PAn polyelectrolyte composite film was investigated in dichloroethane containing CF3COOH and MeOH. Consequently, improvement of ph otoreduction efficiency, as well as inhibition for the decomposition reacti on of the PAn polyelectrolyte composite film was obtained. (C) 2000 Elsevie r Science Ltd. All rights reserved.