Processable polyaniline-titanium dioxide nanocomposites: effect of titanium dioxide on the conductivity

'In-situ' polymerization was carried out in the presence of anatase titanium dioxide (TiO2) to synthesize polyaniline/TiO2 composite (PANI/TiO2). Emeraldine base form of PANI/TiO2 (PANI(EB)/TiO2) composite was reprotonated with anionic surfactant to prepare homogeneous suspension in,m-cresol and chloroform. Conductivity of reprotonated PANI/TiO2 composite film cast from its suspension in m-cresol is higher than that of the film cast from its chloroform suspension due to well-extended conjugation chain of PANI. The anionic surfactant-coated TiO2 suspension and doped PANI solution were combined to form homogeneous suspension and to cast free-standing nanocomposite films with the TiO2 content up to 50 wt.%. Such processable PANI/TiO2 nanocomposite has suitable conductivity (1-10 S/cm) when it is cast from the combined suspension, and it increases after thermal treatment at 80 degrees C for 1 h. It is easy to manipulate the TiO2 content by changing PANI/TiO2 ratio. Also, the nanocomposite film has better quality. (C) 2000 Elsevier Science S.A. All rights reserved.