Robust superhydrophobic silicone/epoxy functional coating with excellent chemical stability and self-cleaning ability

Abstract

Superhydrophobic surfaces have attracted broad attention because of their unique water repellency but are restricted by poor wear resistance, weak adhesion to the substrate, and complex fabrication processes. Herein, a double-layer coating strategy consisting of the amino fluorine–silicone resin/epoxy resin (AFSR/EP) system is created. The system features a high hardness and transparent hydrophobic interface adhesive layer through the amine–epoxy “click” chemical reaction. The environmentally friendly resin system and low-cost nano-silica particles (n-SiO₂) are composited and sprayed onto the substrate surface to form a superhydrophobic layer with outstanding robustness and excellent environmental stability. The prepared AFSR/EP@n-SiO₂ composite coatings have a water contact angle of 161.1° and a sliding angle of 3.4°, demonstrating high superhydrophobic properties. Benefitting from the complementary advantages of silicone/epoxy resin, the prepared composite coatings maintain remarkable water repellency after various harsh environmental tests, including cyclic mechanical abrasion and tape-stripping, acid–base (pH 1 and pH 14) treatment, 10 wt% NaCl (pH 7) salt solution immersion, temperature treatment, knife scratching, and long-term ultraviolet radiation treatment, showing reinforced mechanical robustness and durable anti-corrosion stability. Notably, surface hardness of 5H and optical transparency over 80% can be achieved. The simple method offers a novel approach for the large-scale preparation of multifunctional superhydrophobic coatings.