A Silica-Sol-Based Fortified Structure with Superhydrophobic Coating for Harsh Conditions.

Abstract

Although numerous bio-inspired superhydrophobic coatings have been extensively studied in the last decades, most of them suffer from low chemical stability and mechanical weakness, which severely limit their extensive applications. Herein, a silica-based, superhydrophobic, highly stable and mechanically durable coating was prepared via a facile, energysaving strategy. Modified silica nanoparticles, were fortified with silane coupling agent and spray-deposited on substrates, forming a superhydrophobic, self-cleaning coating with high water contact angle (CA = 159.0°), as well as low rolling angle (RA ≈ 3°). The protective coating showed high chemical stability that endured various harsh conditions, such as wide temperature range (-18 to 250 °C), extreme pH (1 to 13), weeks of exposure under sunlight, etc. Moreover, the coating exhibited superior mechanical robustness that could resist the attack of shear force in vigorous ultrasonication for 7 hours. In addition, repetitive scratching with a steel blade could not undermine the protective coating (CA > 150°). It is believed that the present strategy is a potent candidate for facile fabrication of superhydrophobic surface coatings, which have promising applications on extreme conditions in both household and industry.