A facial approach combining photosensitive sol⿿gel with self-assembly method to fabricate superhydrophobic TiO2 films with patterned surface structure

Abstract

Superhydrophobic TiO2 films with micro-patterned surface structure was prepared through a facial approach combining photosensitive sol⿿gel method with following surface modification by 1H,1H,2H,2H-perfluorooctyltrichlorosilane (PFOTCS). The patterned surface possessed quasi micro-lens array structure resembling processus mastoideus of lotus, leading to excellent hydrophobicity. The relationship between hydrophobic performance and the period of the micro-patterned TiO2 surface was investigated. The water contact angles (CAs) of micro-patterned TiO2 surface increased with the decrease of the periods, and the patterned surface with the lowest period of 0.83μm showed the highest CA of 163°. It suggests that this approach would offer an advantage to control the wettability properties of superhydrophobic surfaces by adjusting the fine pattern structure. Furthermore, the superhydrophobic state could be converted to the state of superhydrophilicity under ultraviolet (UV) illumination as a result of the photocatalytic decomposition of the PFOTCS monolayer on the micro-patterned TiO2 Surface.