Fabrication of transparent wear-resistant superhydrophobic SiO2 film via phase separation and chemical vapor deposition methods

Glass with superhydrophobic, transparent, and wear-resistant properties are quite desirable for the applications in high building glass curtain, wind shield glass, and solar cell cover glass. How to fabricate a superhydrophobic surface with both high transparency and good wear resistance is still a great challenge because roughness and transparency are mutually exclusive. Here, transparent, wear-resistant, superhydrophobic inorganic coating on glass substrate has been successfully achieved by a two-step process combining phase separation and chemical vapor deposition (CVD). Firstly, a wear-resistant inorganic porous film with honeycomb-shaped pores is prepared on the glass surface by applying the phase separation method based on the epoxy resin-silica sol system. The prepared porous structure is used as the micron-level "armor" protective structure. Then nano-SiO2 particles have been deposited on the porous film via CVD method to construct a micro-nano hierarchical structure required for superhydrophobicity on the glass surface. Finally, a superhydrophobic film has been successfully achieved after being modified with fluoroalkylsilane (FAS). The water contact angle (WCA) and water sliding angle (WSA) of the obtained sample are 154.0 ± 0.9° and 3.2 ± 0.2°, respectively. At the same time, it has good transparency with high visible light transmittance and low haze. Its visible light transmittance is as high as 87.7% (only 1.7% less than blank glass) and haze is only 1.87%. Moreover, after 2000 cycles of abrasion under harsh conditions, the film still maintains good hydrophobic properties, and its water contact angle is still higher than 130°. In addition, the prepared functional film also has excellent self-cleaning performance, as well as acid and salt corrosion resistance. The preparation method used here has the advantages of low cost, easy operation, large area preparation, and broad application prospects.