Ultraviolet-Durable Superhydrophobic Nanocomposite Thin Films Based on Cobalt Stearate-Coated TiO₂ Nanoparticles Combined with Polymethylhydrosiloxane

Abstract

Ultraviolet (UV)-durable superhydrophobic nanocomposite thin films have been successfully fabricated on aluminum substrates by embedding cobalt stearate (CoSA)-coated TiO₂ nanoparticles in a hydrophobic polymethylhydrosiloxane (PMHS) matrix (PMHS/TiO₂@CoSA) using the sol-gel process. When compared to the sharp decrease of water contact angle (WCA) on the superhydrophobic PMHS/TiO₂ thin films, the PMHS/TiO₂@CoSA superhydrophobic thin films exhibited a nearly constant WCA of 160° under continuous UV irradiation for more than 1 month. The designed scheme of the TiO₂@CoSA core-shell structure not only increased the hydrophobic properties of the TiO₂ nanoparticle surface but also confined the photocatalytic efficiency of TiO₂ nanoparticles. A plausible model has been suggested to explain the UV-durable mechanism of the superhydrophobic nanocomposite thin films based on PMHS/TiO₂@CoSA. Furthermore, the elongated lifetime in the exposure of the solar light imparts this superhydrophobic nanocomposite thin film with potential practical applications where UV-resistant properties are emphasized including corrosion-resistant building walls, anti-icing airplanes, self-cleaning vehicles, and so forth.