Characterization of a flexible self-cleaning film with photoinduced hydrophilicity comprising phosphonic-acid-modified polysilsesquioxane-anchored titanium dioxide

•Creation of transparent and flexible self-cleaning film comprised of titania.•Phosphonic-acid-modified polysilsesquioxane was synthesized as an important layer.•Self-cleaning film showed wettability and photodegradation of methylene blue.•The photocatalytic ability was maintained after one-year-worth durability test. Self-cleaning materials with photoinduced hydrophilicity have received significant attention. These materials have been applied to rigid and flat substrates such as glasses and ceramics; however, their utilization on flexible substrates is necessary for their future applications. Herein, the preparation of a flexible and transparent self-cleaning film with photoinduced hydrophilicity is reported. The self-cleaning film was developed using three layers, namely, TiO2 as a cleaning layer, phosphonic-acid-modified polysilsesquioxane (PAPS) as a protective and anchoring layer, and poly(bisphenol A-co-epichlorohydrin) (PBE) as a plastic supporting layer. The surface morphology, transmittance, photoinduced hydrophilicity, and organic dye photodegradation ability of the self-cleaning film were evaluated. The free-standing film demonstrated high flexibility and transparency. Moreover, water contact angle of this TiO2/PAPS/PBE film changed to ~5° from 34° under UV irradiation. Furthermore, durability of the film was investigated via photocatalytic tests by examining the water contact angle, degradation of methylene blue, and appearance of the film under conditions that replicated a service life of one year. The TiO2/PAPS/PBE film exhibited photocatalytic activity and its appearance was superior to that of the TiO2/PBE film.