One-step fabrication of durable, self-cleaning, anti-icing and UV-shielding coatings

Abstract

Glass is widely used in many different areas and applications. In particular, when used in buildings, the high light transmittance and hydrophilic nature of glass can cause problems, such as poor UV protection and dust accumulation. The application of photochromic coatings can improve the optical and self-cleaning properties of glasses. In this study, self-cleaning, UV-shielding glass coatings were fabricated through a one-step, efficient method using spiropyran and SiO₂/polydimethylsiloxane. This superhydrophobic coating, featuring a water contact angle of 153°, exhibited a transmittance of 82–85 % in the visible range. Upon exposure to ultraviolet (UV) radiation, the spiropyran molecule transforms into its merocyanine (MC) form, effectively providing approximately 80 % shielding within the 300–400 nm wavelength range. The merocyanine form spontaneously reverts to the spiropyran form in the absence of UV light. The coating demonstrated exceptional ice-delay performance, postponing ice formation by 389 s compared with that of bare glass. It also demonstrated remarkable stability with 25 cycles of sandpaper abrasion while preserving its structural and functional integrity under diverse conditions, including immersion in organic solvents, exposure to acidic and basic environments, and prolonged UV irradiation for 10 h. This work demonstrates a simple, scalable, and durable approach for developing multifunctional glass coatings that enhance UV protection and self-cleaning properties and offers a promising solution for next-generation smart building materials and sustainable surface technologies.