The Preparation and Performance of Dual-Resin-Based Composite Superhydrophobic Coatings

Abstract

A functionally complementary dual-resin strategy was developed to regulate wettability and mechanical durability in superhydrophobic coatings. High-impact polystyrene (HIPS) and organic silicone resin (OSR) formed the composite matrix, and coatings with different HIPS/OSR ratios were fabricated by one-step spraying at a constant fluorinated nano-SiO₂ loading. SEM/EDS, surface roughness, and XPS analyses indicated that increasing the OSR proportion reduced smooth HIPS-rich domains, promoted continuous OSR/fluorinated-silica-rich micro-nanostructures, and increased surface fluorine exposure, thereby increasing the water contact angle and decreasing the sliding angle. Mechanical tests revealed a composition-dependent trade-off: HIPS-rich coatings showed smaller contact-angle losses, whereas OSR-rich coatings better retained low sliding angles after damage. The 1:2 HIPS/OSR coating achieved the highest initial water repellency (158.85° contact angle; 5.55° sliding angle), remained stable after acidic and alkaline immersion, delayed complete freezing to 1260 s at −15°C, exhibited effective self-cleaning, and maintained approximately 96% oil–water separation efficiency over 5 cycles. These results establish a composition–structure–surface chemistry–performance relationship and identify resin composition as a practical design variable for balancing water repellency and mechanical durability.