Surface-engraved nanocomposite coatings featuring interlocked reflection-reducing, anti-fogging, and contamination-reducing performances

The competing constraints, associated with different features such as wettability, optical transparency, anti-reflectivity, and anti-fouling properties, set back the progress of developing multi-functional coatings in an easily-accessible manner. Herein, polyvinyl alcohol (PVA)/SiO2 coatings with combined reflection-reducing, anti-fogging, and underwater contamination-reducing performances were successfully fabricated from the immersion-curing process assisted with ultrasonic dispersion of silica nanoparticles (NPs). The effects of SiO2 dispersion method, thickness and SiO2 particle size on surface properties were systematically investigated. The designed two-stage process was underlined for the first time to be pivotal, during which the initial ultrasonic dispersion rendered the coating transparent, while immersion-curing further repressed its surface reflection. Coexistence of high hydrophilicity with high transmittance has been realized in the as-prepared coatings containing highly-dispersed fumed silica A200 NPs, resulting in a multi-functional surface equipped with anti-fogging, anti-reflection, self-cleaning and underwater anti-fouling properties. Additionally introducing bi-component acrylic polyurethane basecoat, the PVA/SiO2 coatings were applicable on diverse substrates, including fragile ones.