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

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, energy-saving 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 degrees), as well as low rolling angle (RA approximate to 3 degrees). The protective coating showed high chemical stability that endured various harsh conditions, such as wide temperature range (-18 to 250 degrees 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 degrees). 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.