Green preparation of transparent superhydrophobic coatings with persistent dynamic impact resistance for outdoor applications

Abstract

Transparent superhydrophobic surfaces are employed in a wide range of outdoor applications, such as windshields and house windows. However, micro-nano hierarchical superhydrophobic structures are vulnerable to impacts from sand particles and rain drops. The low impact resistance limits the practical applications of superhydrophobic surfaces. Herein, we develop a novel eco-friendly self-assembly process in aqueous medium to construct transparent superhydrophobic surfaces with high dynamic impact resistance. The transmittance of the prepared surfaces was ~ 94.2% compared with the transmittance of the pure glass substrate. The surface is resistant to the impact of 600 g sand and an ~ 8.6 m/s of water jet applied for 6 min (this is nearly 1500 times higher than the annual precipitation in the tropics), which makes the superhydrophobic surface sustainable in heavy rain. Furthermore, the coating was resistant to highly corrosive media (sulfuric acid) in the case of acid rain and UV illumination. A combination of these properties is attractive for transparent applications with self-cleaning properties, waterproofing and environmental stability.