Abstract: Nanocrystalline anatase TiO2 films with indium tin oxide(ITO) coated glass as the film substrate were fabricated through spin-coating technique. The TiO2 pastes were prepared with sodium dodecylbenzenesulfonate(DBS) modified TiO2 nanocrystals, synthesized by sol-hydrothermal processes in advance, together with different amounts of polyethylene glycol(PEG) macromolecules. The as-prepared films were mainly characterized by ultraviolet-visible (UV-Vis) spectroscopy, field emission scanning electron microscopy(FE-SEM) and water contact angle(WCA) measurement. Effects of the addition of DBS and PEG on the wetting performance of the resulting films and relevant mechanisms were principally investigated. The results show that the as-prepared film displays super-hydrophilic property after co-addition of DBS and PEG although it is not exposed to ultraviolet light prior to the WCA measurement. This appealing result is mainly attributed to the produced micro- and nanometer-scale hierarchical surface structure with uniformly dispersed micro papillae. Each papilla was made up of a great number of TiO2 nanoparticles. The possible formation mechanisms related to the DBS amphiphilic property of the characteristic surface were also suggested. Moreover, the resulting film also exhibits considerable durability in the superhydrophilicity, which is very useful for practical application in self-cleaning, anti-fogging, and bacteria-resistant fields.

Key words: Thin film, Chemical synthesis, Surface property