One-step spraying to fabricate nonfluorinated superhydrophobic coatings with high transparency

Designing multifunctional and fluorinate-free liquid-repellent materials via a facile and scalable method is highly desired. Herein, a transparent, durable, and self-cleaning superhydrophobic coating based on trimethoxypropylsilane-silica nanoparticles sol solution was prepared by one-step process. Once spray deposited on glass substrates, the transparent superhydrophobic self-cleaning glass with high water contact angle (158.5°) as well as low sliding angle (3.9°) was obtained. The transmittance of coated glass substrates is above 80 % in visible-light region (400–800 nm). Moreover, the prepared coatings kept stable superhydrophobicity under extreme environment conditions of high temperature and humidity, high or low temperature, and UV light irradiation. Water droplets could still roll off the obtained surface easily after examined by water impact and lacerating the surface with a knife. In addition, this versatile and environmentally benign approach can be applied on wide substrates readily by using spraying or dipping technique without any extra surface treatments. Therefore, our method may provide extensive applications in optoelectronics, liquid-repellent coatings, and oil–water separation.