Study On Preparation And Performance Of Titania Nanopartices And Its Application

Nanometer titania has been widely used in such fields as semiconductor, catalyst and functional finishing of textile because of its stable chemical property, no toxicity, low cost, reasonable photocatalytic and UV resistance performance. Photocatalyst is the key part in photocatalysis, and further improvement on its activity, efficiency and UV resistance by selective treatment to modify the properties of the particles is an essential step to apply this novel technology. In this dissertation, titania nanoparticles (nano-TiO2) were prepared by microemulsion, sol-gel and low-temperature hydrolysis process. The photocatalytic activity and UV resistance finishing capacity of modified nanoparticle TiO2have been characterized by UV-VIS、TG-DTA、 IR、XRD、SEM、TEM.Titania nanoparticles were prepared by microemulsion process with titanium chloride and aqueous ammonia in Triton X-100/n-butyl alcohol/cyclohexane. Particle size of the hydrated TiO2increases with increase in reaction time as well as surfactant-to-water molar ratio. Hydrated TiO2was calcined at650℃and1000℃and characterised by UV-VIS, TGA, DTA, XRD and TEM analyses. XRD and TEM results demonstrate that the anatase and rutile nano-TiO2possess better dispersity, with particle size20-35nm and40-60nm respectively.The rare earth(Gd, Ce, La) doped and the double metallic ions (Ce-Cu, Ce-Ag) doped titania nanoparticles were prepared by a sol-gel process with Ti(OC4H9)4as precursor and characterized by XRD, TEM and UV-VIS. The morphologies of the particles varied with the doping condition. The rare earth doping increases the phase transition temperature converting anatase phase into rutile phase. The double metallic ions doping decreases the phase transition temperature. The doping (either the rare earth doping or the double metallic ions doping) can decrease the grain size of TiO2particles, which was8-16nm. The photocatalytic activities of the doped nano-TiO2were investigated by the photocatalytic degradation of methyl orange under ultraviolet lamp. The results showed that the photocatalytic performance of TiO2and UV resistance of finished fabrics was enhanced greatly owing to doping ions.Titania nanoparticles were prepared through low-temperature hydrolysis, and the initial material was Ti(OC4H9)4. Anatase, rutile and mixed nano-TiO2were synthesized by changing the ratio of initial materials and reaction time, and were wrapped with lmol·l-1sodium silicate. XRD, TEM, UV-VIS, IR and TG spectra were employed to characterize the nanometer particles. The photocatalytic activities of the samples were investigated by the photocatalytic degradation of methyl orange. The results revealed that the photocatalytic activity was excellent when TiO2powers contain69.8%anatase and30.2%rutile phase, and methyl orange was degraded by95.7%. The cotton fabrics were finished by nano-TiO2and its clothing performance was tested and analyzed. The results revealed that functional finishing on cotton fabrics was feasible by liquid phase at low temperature, the ultraviolet transmitting rate changed a little after10times of washing, and the fabrics treated with the finishing agent had excellent UV resistance and wear ability. UV resistance of the fabrics is best when SiO2:TiO2is5%.