Preparation of a wear-resistant, superhydrophobic SiO2/silicone-modified polyurethane composite coating through a two-step spraying method

The preparation of superhydrophobic coatings has been extensively researched, but their practical applications are limited by complicated preparation processes and poor mechanical durability. This study proposed a simple, low-cost method of preparing superhydrophobic coatings. A nano-silica dispersion was sprayed onto a semi-cured silicone-modified polyurethane resin through a two-step spraying method. Subsequently, these materials solidified together to successfully prepare a superhydrophobic coating with 159 degrees contact angle and 2 degrees sliding angle. The prepared silica/silicone-modified polyurethane (SiO2/SiPU) superhydrophobic coating showed superhydrophobic property after being cyclically rubbed for 30 cycles on 1000-mesh sandpaper under a load of 200 g. The coating further exhibited good corrosion resistance when placed in strong acid and alkali environments and excellent self-cleaning properties in air. This simple and environmentally friendly approach may have enormous application potential in many fields.