A durable superhydrophobic coating based on inherent nano/micro-integrated materials

Superhydrophobic coating has been a research focus due to its self-cleaning, anti-fouling, anti-corrosion resistance properties, etc. However, poor durability of superhydrophobic coating affects its service life. In this study, we develop a durable superhydrophobic polyester (PE)/SiO₂-perfluorooctyltriethoxysilane (PFOTES) (PSP) coating using a dual-spraying method. Two grades of mesoporous SiO₂ particles with inherent nano/micro-integrated (NMI) geometry are successfully embedded into organic PE matrix achieving a stable rough structure under the action of interfacial wetting and chemical-bonding, which greatly reduces the difficulty in constructing hierarchical structure. The micro-scale particles work as both the microstructure important for the superhydrophobic surface and a protective framework for the nanostructure, and thus improve the robustness of superhydrophobic coatings. Significantly, the newly exposed low-surface-energy nanopore feature of PSP coatings are advantageous in maintaining a stable superhydrophobicity after being abraded, and the PSP coatings display good adhesion performance because of dual-interfacial interactions. Moreover, the superhydrophobic coatings possess excellent self-cleaning, anti-fouling and bouncing performances, and they can retain superhydrophobicity after a prolonged exposure to ultraviolet radiation and immersion in strong acid/alkaline solutions. Porous SiO₂ particles, taking advantage of its superiority as an NMI structural material, provide a promising candidate for preparing durable superhydrophobic coatings endowing with necessary stable hierarchical roughness.