Fabrication of multi-substrate hydrophobic surfaces based on low-cost nanosilica dispersion

A low-cost, fluorine-free, transparent nanosilica dispersion was synthesized via in situ grafting modification. The nanosilica dispersion was applied to various substrates using a simple brushing method to fabricate hydrophobic surfaces. The silica nanoparticles, averaging ~40 nm in diameter, were surface-functionalized with a high density of methyl groups, contributing to an organic content of approximately 12 wt%. The nanosilica dispersion was easily applied to different substrates and imparted excellent hydrophobicity, with water contact angles exceeding 130°. Durability tests, including prolonged water immersion and sandpaper abrasion, demonstrated good stability of the coating. Furthermore, the nanosilica-coated concrete surfaces exhibited excellent de-icing performance.