Study Of Self-cleaning Fabrics Based On Photocatalysis Of Nano TiO₂

Photocatalytic self-cleaning fabric has drawn great attention due to its water-saving, energy conservation, less detergent costs and environmentally friendly. As one of the most popular photocatalytic materials, nano TiO₂ owns high photo-catalytic activity, small size, large specific surface area, lower price and perfect preparation technology. In this dissertation, the variation of surface properties, the effective load factor, durability, visible light catalysis activity of the nano TiO₂ were studied systematically. The main research contents and conclusions are summarized as follows:1. Preparation and characterization of PA6 self-cleaning fabric. Nano TiO₂?Degussa P25? was loaded onto the surface of UV irradiated polyamide 6 fabric combined with ultrasonic wave, and the variation of surface microstructure of the fabric was investigated by Fourier transform infrared spectroscopy?FT-IR?, Scanning electron microscope?SEM?, Energy-dispersive spectrometer?EDS? and X-ray photoelectron spectroscopy?XPS?. The results indicated that the chemical bond was formed between nano TiO₂ and PA6 fabric, which enhanced the loaded stability of nano particles. The surplus of nano TiO₂ onto the surface of PA6 fabric was greater than 85% after 5 times decomposition recycling experiments of methyl orange solution. The ultraviolet protection factor?UPF? of prepared self-cleaning fabric about 50+, antibacterial rate was about 99%, and the water contact angle certain to exceed 150 o, the fabric owns the super-hydrophobic performance. In addition, the modified nano TiO₂?PVAD-TiO₂? was prepared by coating polyvinyl alcohol?PVA?, and the PVAD-TiO₂-PA6 fabric was obtained by UV irradiation and ultrasonic wave. The test results showed that the fabric possess the greater UV-protection property, antibacterial property, super-hydrophobic performance and good visible-light degradation ability.2. Preparation of Fe doping nano TiO₂?Fe-TiO₂? with good visible-light catalytic activity. By titanium tetrachloride?TiCl4? as titanium source, the Fe doping nano TiO₂?Fe-TiO₂? was prepared at cold condition. The crystal structure, photocatalytic mechanism and properties were studied systematically with the combination of transmission electron microscope?TEM?, SEM, X-ray diffraction?XRD? and UV-diffused reflectance spectrum?UV-DRS?. The results indicated that the particle size of Fe-TiO₂ was about 4-8nm, the energy gap of nano TiO₂ has declined by 0.3eV after doping by Fe, which improved the visible light catalysis activity. And the photo-catalytic efficiency of Fe-TiO₂ was about 15.4 times higher than pure nano TiO₂. The modified cotton fabric was obtained by loading Fe-TiO₂ particles, and then the load stability was tested by simulating the real washing environment. The surplus of nano Fe-TiO₂ onto the surface of cotton fabric was greater than 90% after 60 times washing simulating experiments.