In-situ Growth Of Nanometer TiO₂on The Surface Of Wool Fibers And Compound Staining

Wool fiber acted as an important raw material in the textile industry are widelyused for the clothing, blankets and decorations because of its unique characteristicssuch as soft luster, good elasticity, high moisture regain, excellent warmth.Nano-scaled titanium dioxide having strong photocatalytic activity, antibacterial andultraviolet shielding performance is widely applied for the functional textiles. Thefunctional fibers can be modified or prepared using different methods. In this paper,Nano-sized titanium dioxide particles prepared by hydrothermal precipitation methodwere directly immobilized on the surface of wool fiber using tetrabutyl titanate.Titanium dioxide nanoparticles were doped with N element to improve thephotocatalytic activity and self-cleaning ability. Chitosan used as a dispersant wasmixed with the precursors during the hydrothermal treatment to improve the dyeuptake and K/S value. The surface of wool fiber was loaded with a layer of titaniumdioxide nanoparticles, and simultaneously dyed with reactive dye. Scanning electronmicroscope (SEM), transmission electron microscope (TEM), infrared spectroscopy(IR), thermal gravimetry (TG), differential scanning calorimetry (DSC), X-raydiffraction (XRD), diffuse reflectance spectrum (DRS) and X-ray photoelectronspectroscope were employed to characterize the surface morphology, microstructure,chemical composition, thermal stability, phase structure and optical properties of woolfibers before and after treatments. The properties of density, tensile, surface frictionaleffect and self-cleaning performance were also measured. The results can beconcluded as following:(1) After being modified with tetrabutyl titanate under hydrothermal conditions,the surface of wool fiber was covered with a thin film of anatase titanium dioxidenanoparticles with an average size of5nm or so. Compared with the original woolfibers, the thermal stability of TiO2-coated wool fibers changed a little. The anti-ultraviolet irradiation and self-cleaning capability were also obtained. The densityincreased due to the TiO2coating. The tensile properties decreased to some extent.The friction coefficient increased while the frictional effectiveness decreased.(2) N-TiO2nanoparticles were prepared using tetrabutyl titanate as the precursorand ammonium chloride as the nitrogen source by hydrothermal method. Thephotocatalytic activities and self-cleaning capability were improved by incorporatingthe nitrogen element. Moreover, chitosan was added into the tetrabutyl titanateprecursor solution to treat wool fibers. The dye uptake and dyeing depth ofTiO2-coated wool fiber were improved.(3) Wool fibers loaded with a layer of titanium dioxide nanoparticles were dyedusing tetrabutyl titanate as the precursor and Lanasol Blue3G as the dye byhydrothermal method. The particle size of as-prepared titanium dioxide was less than10nm. The color fastness to sunlight of TiO2-coated and dyed wool fibers wasimproved. The chemical structure was not changed. The thermal stability was changedbut not too much. The ultraviolet absorbing capability was enhanced, which couldphotodegrade the methylene blue dye.