Optically transparent superhydrophobic surfaces with enhanced mechanical abrasion resistance enabled by mesh structure.

Inspired by naturally occurring superhydrophobic surfaces such as "lotus leaves", a number of approaches have been attempted to create specific surfaces having nano/microscale rough structures and a low surface free energy. Most importantly, much attention has been paid in recent years to the improvement of the durability of highly transparent superhydrophobic surfaces. In this report, superhydrophobic surfaces are fabricated using three steps. First, chemical and morphological changes are generated in the polyester mesh by alkaline treatment of NaOH. Second, alkaline treatment causes hydrophobic molecules of 1H,1H,2H,2H-perfluorodecyltrichlorosilane to react with the hydroxyl groups on the fiber surfaces forming covalent bonds by using the chemical vapor deposition method. Third, hydrophobicity is enhanced by treating the mesh with SiO2 nanoparticles modified with 1H,1H,2H,2H-perfluorooctyltriethoxysilane using a spray method. The transmittance of the fabricated superhydrophobic mesh is approximately 80% in the spectral range of 400-1000 nm. The water contact angle and the water sliding angle remain greater than 150° and lower than 25°, respectively, and the transmittance remains approximately 79% after 100 cycles of abrasion under approximately 10 kPa of pressure. The mesh surface exhibits a good resistance to acidic and basic solutions over a wide range of pH values (pH 2-14), and the surface can also be used as an oil/water separation material because of its mesh structure.