Substrate-Versatile Approach to Robust Antireflective and Superhydrophobic Coatings with Excellent Self-Cleaning Property in Varied Environments.

Robust antireflective and superhydrophobic coatings are highly desired in wide applications, such as optical devices, solar cell panels, architectural and automotive glasses, lab-on chip systems, and windows for electronic devices. Meanwhile, simple, low-cost, and substrate-versatile fabrication is also essential toward real applications of such coatings. Herein, we developed a substrate-versatile strategy to fabricate robust antireflective and superhydrophobic coatings with excellent self-cleaning property in varied environments, including air and oil and after oil contamination. A mixed ethanol suspension, which consists of 1H,1H,2H,2H-perfluorooctyltriethoxysilane modified dual-sized silica nanoparticles and acid-catalyzed silica precursor, was first synthesized. The acid-catalyzed silica precursor could help to form a highly cross-linked silica network by connecting the silica nanoparticles, thus significantly enhancing the robustness of coatings. The as-prepared coatings were able to withstand a water drop impact test, sand abrasion test, tape adhesion test, and knife and pencil scratching tests. More importantly, it was also found that the wettability and self-cleaning property of coatings after oil contamination were surprisingly different from those in air and oil. These observations are explainable by the alteration of interface; i.e., the alteration of interface has significant effects on the functional properties of coatings. Additionally, the mixed suspension could be sprayed onto various hard and soft substrates including glass, polyethylene terephthalate (PET), polycarbonate (PC), and poly(methyl methacrylate) (PMMA), opening up a feasible route toward varied practical applications in solar cell panels, optical devices, architectural and automotive glasses, droplet manipulators, and fluid control.