| Nano-titanium dioxide has recently attracted widespread concerned because of its uniqueperformances. The hydrothermal method has been employed to prepare the nano-scaledtitanium dioxide having different crystal phases, particle sizes and morphologies bycontrolling the reaction temperature, time, the amount of precursor, etc. Cotton fibers arewidely used in the textile industry due to their unique characteristics, such as high moistureabsorption, air permeability, soft handle and good warmth. However, the use of cotton fibersfor clothing is restricted because of the disadvantages with respect to some other fibers.In this paper, cotton fibers are treated by the hydrothermal synthesis treatment. Theeffects of hot water with high pressure on the structure and properties of cotton fibers are firststudied. The reaction temperature and time are then optimized for different precursors underhydrothermal conditions. Second, a thin film of titanium dioxide nanoparticles is immobilizedon the surfaces of cotton fibers using tetrabutyl titanate or titanium sulfate as the precursorwith or without dispersants like cetyl trimethyl ammonium bromide (CTAB) and chitosan.The titania coated cotton fibers are modified with the silane coupling agents. Finally, cottonfibers are finished with tetrabutyl titanate as the precursor in the presence of ReactiveTurquoise Blue KN-G by hydrothermal process. The morphology, chemical structure,microstructure, thermal stability and optical properties of cotton fibers before and aftertreatmens are characterized by various techniques, such as scanning electron microscopy(SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR),transmission electron microscopy (TEM), thermal heavy (TG), differential scanningcalorimetry (DSC), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance spectrum(DRS). The properties of tensile, surface friction, dye-uptake, K/S value, self-cleaningperformance are also investigated. The results show that compared with the untreated cottonfibers, the tensile properties of cotton fibers after treatmen with hot water decrease. Thefriction coefficient decreases slightly and the surface becomes smooth. The chemical structureand thermal stability change a little. After being treated with titanium sulfate, urea and CTAB,a layer of anatase phase titanium dioxide nanoparticles are loaded on the surface of cottonfiber. The average particle size of titania is less than10nm, which is grafted onto fiber surface.The as-prepared cotton fibers has the capability of anti-ultraviolet irradiation. The frictioncoefficient increases to some extent. The self-cleaning properties are obtained too. Moretitanium dioxide nanoparticles adhered on fiber surface are found after treatment with thecoupling agent. The ultraviolet blocking, friction coefficient, and self-cleaning performanceare enhanced. The dye up-take and dyeing depth of treated cotton fibers increase by addingthe chitosan. A layer of titanium dioxide nanoparticles is immobilized on fiber surface, and simultaneously dyed with Reactive Turquoise Blue KN-G by one-step hydrothermal process.The as-obtaied cotton fibers having a strong absorption to ultraviolet light can photodegradethe strawberry juice. The dyeing depth and dye up-take increase significantly. |
