Preparation And Performance Study Of Temperature-sensitive Titanium Dioxide Films

This article adopted a simple and feasible method to produce temperature-sensitive TiO₂ films,the films with photocatalytic property of TiO₂ can be used for treatment of various gas or liquid pollutants and sterilization;meanwhile,the thermo-sensitivity of films endowed by PNIPAAm is expected to be applied in bacteria stripping from substrates at low temperature after degerming to reach self-cleaning effect.First,TiO₂ films were prepared by sol-gel method on aluminum substrate.Then thermo-sensitive polymer PNIPAAm was fixed on TiO₂ films by coating method to produce temperature-responsive photocatalytic films.Finally the photocatalytic property and stability of films were studied.The main research contents are as follows:?1?First,TiO₂ sol was prepared by materials of tetra-n-butyl titanate?TBT?,anhydrous ethanol,deionized water and acetly acetone?acac?.Then TiO₂ films were prepared by sol-gel method on aluminum substrates,followed by fixing thermo-sensitive polymer PNIPAAm on TiO₂ films to produce temperature-responsive photocatalytic films.The crystal form,surface morphology,structure,elements content and surface wettability of films were detected respectively using XRD,Raman,SEM,IR,XPS and optical contact angle measuring device.The results showed that anatase Ti O₂ films can be obtained by choosing appropriate film-forming conditions and thermo-sensitivity of TiO₂-PNIPAAm film was proved by dynamic change of water contact angle on surfaces at 45? and 25?.?2?Photocatalytic efficiency of films was studied with organic dye methylene blue?MB?as target degradation product,the influences of initial concentration and illumination time on photocatalytic rate were explored.The results showed that PNIPAAm/ TiO₂ films prepared not only retained photocatalytic performance of TiO₂,but also had thermo-sensitivity.Photocatalytic efficiency of films grow with time increasing and initial concentration of solution decreasing.At room temperature,phototcataltic rate of TiO₂ and PNIPAAm /TiO₂ films degradating MB solution can reach 50.5% and 49.1% respectively.But when teperature rose to 45?,degradation rates of TiO₂ and TiO₂/PNIPAAm films remained constant and dropped to 23.4% respectively.?3?Stability of films was tested.The results showed that photocatalytic stability of films in cyclic utilization are good and that catalytic activity of films dropped to a certain extent when exposed to indoor air,but decreased significanly when soaked in water at room temperature.