TiO2/polyaniline nanocomposite films prepared by magnetron sputtering combined with plasma polymerization process

Radiofrequency plasma polymerization in combination with direct current reactive magnetron sputtering is utilized for the synthesis of TiO₂/plasma polymerized aniline nanocomposite thin films. In the composite film, X-ray diffraction measurements reveal formation of nanocrystalline rutile TiO₂ of crystallite size 3.6 nm. Due to continuous bombardment of plasma species during simultaneous magnetron sputtering and plasma polymerization, the precursors of polymerization are broken and few functional groups are retained in the composite film. The plasma polymerized aniline has the direct optical band gap of 3.55 eV and the nanocrystalline rutile TiO₂ is wide gap semiconductor with indirect gap of 3.20 eV which suggests the existence of an energy barrier at the interface in the composite form. The ac conductivity of composite film shows significant improvement as compared to plasma polymerized aniline film and sputtered rutile TiO₂ film. The composite film may find potential application as antistatic coatings.