In situ polymerized polyaniline films. 2. Dispersion polymerization of aniline in the presence of colloidal silica

Composite polyaniline-silica films produced on glass surfaces during the di spersion polymerization of aniline in the presence of colloidal silica were investigated. The film morphology and composition were characterized by FT IR, W-vis, and X-ray photoelectron spectroscopies. Compared with pure polya niline films produced under similar conditions, the composite films are thi nner and smoother, and their surface is silica rich. The film thickness of both pure and composite films decreased as the polymerization temperature i ncreased from 0 to 50 degrees C. To determine the particle size of polyanil ine-silica dispersion particles, which are formed at the same time as the f ilms, dynamic light scattering was used. The correlation between the partic le size and film thickness is discussed. The electrical conductivity of com posite polyaniline films was only a little affected by the presence of sili ca.