Synthesis and characterization of porous TiO2 and its application in hydrophilic coatings

A sol–gel and phase separation method were employed to synthesize porous TiO₂ coating materials, which were applied to two types of transparent substrates. The coating preparation process is simple, cost-effective, and allows for the adjustment of pore structures. The study investigated the impact of the microstructure, substrate, and UV light exposure on the hydrophilic properties of the TiO₂ coating materials. The results indicate that the hydrophilicity of TiO₂ coating materials prepared with resin as the substrate is inferior to that of similar coatings prepared with glass as the substrate. Furthermore, the hydrophilic performance of glass substrates coated with porous TiO₂ is superior to those coated with dense TiO₂. Glass substrates coated with porous TiO₂ exhibit superhydrophilicity after 1 h of UV light exposure. The hydrophilic mechanism of the coating material surface was analyzed using surface energy theory, capillary theory, and photo-induced hydrophilic theory.