Comparison of the electrochromic properties of films made of silica/polyaniline composite nanoparticles and films made of pure polyaniline

In this study, we demonstrated that the electrochromic properties of silica/polyaniline nanocomposite films are superior to those of films made of pure polyaniline. The silica/polyaniline composite particles were synthesized using an inverse microemulsion method. The composite material was deposited on the FTO-coated glass by a spin coating. To compare the electrochromic properties with the pure polyaniline film, characterizations such as cyclovoltammetry, visible transmittance spectroscopy, and color contrast measurements were performed on both the films. The comparison showed an increase of durability for the composite film. This stability enhancement in the composite film was ascribed to the suppression of the formation of highly oxidized forms such as pernigraniline. This suppression is believed to come from the protective effect of silica in the composite nanoparticles.