Durable, Transparent, and Superhydrophobic Film Design for Flexible Substrate

Abstract

Transparent superhydrophobic films/coatings have recently gained significant attention in the solar energy field due to their ease of preparation, low cost, self-cleaning process, and high effectiveness in reducing dust adhesion to the surface. Compared to the rigid glass cover, the organic one has an advantage of flexibility and light weight, but the dust deposition impact is more serious. The aim of the present study is to design a transparent and superhydrophobic film with good durability on the organic glass surface, to recover the module efficiency reduction caused by dust deposition. Based on a soft photolithography and hot-pressing process, periodic microcavities are prepared on the organic glass surface as an armor structure, and hydrophobic SiO₂ nanoparticles are sprayed into the microcavities to achieve anti-reflection and superhydrophobicity. The experimental test results show that the designed film possesses a large contact angle around 160°, a sliding angle of 3°, and a high visible transmittance over 90%. The unique armor structure design greatly improves the wear resistance of the film, and after encountering harsh conditions such as sandpaper friction, water flow impact, acid immersion, UV exposure, and repeatable bending, it still maintains excellent superhydrophobicity.