Facile synthesis of transparent superhydrophobic titania coating by using soot as a nanoimprint template

This paper develops a robust method for the facile synthesis of transparent superhydrophobic TiO2 film by using the flame soot layer as a nanoimprint template. After the nanoimprint and calcination process, the TiO2 coating exhibited the inverse roughness structure of the soot layer with high transparent properties. And subsequent hydrophobic modification with 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (FAS) rendered the transparent surfaces superhydrophobic (168 +/- 4 degrees for water). The transparency and superhydrophobicity of the TiO2 coating could be controlled by adjusting the initial concentration of the TiO2 suspension. The coating possesses excellent chemical stabilities and good mechanical resistance. Moreover, a superhydrophobic-superhydrophilic micropattern was further fabricated by illumination with ultraviolet light through a photomask. This fabrication process is expected to be extended to other transparent superhydrophobic coatings and to be used in many research fields.