Influence of sol composition on natural superhydrophilicity of sol gel–derived TiO₂–SiO₂ nanocomposite thin films

TiO₂–SiO₂ nanocomposite thin films have been deposited via a sol-gel route. These films exhibit a natural and persistent superhydrophilicity, which allows considering new applications for easy to clean surfaces. Influence of the sol composition on the composite film morphology and thickness has been studied by atomic force microscopy, scanning electron microscopy, transmission electron microscopy, and ellipsometry measurements. The wettability of nanocomposite films has been studied and discussed in relation to morphology and thickness features. It is concluded that, while such features can influence the wettability of nanocomposite films, intrinsic effects arising from their TiO₂–SiO₂ composition probably play a predominant role.