Design and synthesis of robust superhydrophobic coating based on epoxy resin and polydimethylsiloxane interpenetrated polymer network

Superhydrophobic surfaces, such as lotus leaves, have attracted significant attention because of their excellent performance and potential application value. However, the micro-nano hierarchy on superhydrophobic surfaces is often vulnerable and easily broken from mechanical stress or chemical corrosion, which greatly inhibits its practical application and long-term service. This study presents a low-cost and scalable superhydrophobic coating based on an interpenetrated polymer network of polydimethylsiloxane (PDMS) and epoxy resin. The composite polymer matrix exhibits mechanical robustness as derived from the epoxy resin and low surface energy as derived from the PDMS. The superhydrophobic coating is obtained by dispersing fluoroalkyl-silane-modified SiO2 in the solution containing the composite polymer. The multi-level hierarchical structure of SiO2 aggregations and their strong bonding with the composite polymer gives the coating outstanding mechanical durability while maintaining superhydrophobicity after multiple cycles of sandpaper abrasion, tape peeling, and water impact tests. The chemical inertness of all components ensures its chemical stability, and the surface shows super repellency to strong acids and alkaline liquids (pH = 0–14). The coating also has excellent self-cleaning properties, which has potential applications in various industrial fields.