Functional Finshing Of Cotton And Bombyx Mori Silk Fabrics With Nano-titania

With the rapid progress of living standards, people have great demands of multifunctional textiles with hygienic, easy maintenance, UV resistant and self-cleaning purposes, etc. The solgel technology, together with some special finishing agents, makes it possible to achieve textiles with multi-purposes with better qualities and add-on values. As the most commonly used natural fibers, cotton and Bombyx mori(B. mori) silk can be treated with nano-materials. It is of great importance to investigate the fiber abilities and fabric performances that finished by nanotechnologies.Preparation and application of nano-Ti O2 sols containing citric acid were studied. By applying the as-prepared sols, cotton fabrics with excellent UV resistance, anti-wrinkle abilities, and good whiteness were obtained. Compared with unfinished samples, the finished sample achieve 5.5 times￠ Ultraviolet Protection Factor(UPF) with 33.5% higher dry crease recovery angle after five-time￠s washing. Results show that the diameter distribution of the sol is righttailed with an average diameter of 72.8 nm. Agglomeration of nano-Ti O2 particles on fiber surfaces was demonstrated with Field Emission Scanning Electronic Microscope(FE-SEM) and Energy Dispersive X-ray Spectrometer(EDS). Esterification between citric acid and cellulose was proved by infrared spectra.Nano-Ti O2 sols of aqueous and ethanol system were prepared with the precursor of Tetrabutyl orthotitaniate(TBT) and applied on B. mori silk fabrics respectively. Anatase phase Ti O2 is mainly exist in aqueous systems while anatase and rutile are about each one half in ethanol system with smaller sizes. UV radiation can accelerate the transformation from anatase to rutile. Varieties of thermal decomposition of sols prepared by different methods were investigated by Thermal Gravimetric and Differential Scanning Calorimeters(TG-DSC). Agglomeration of nano-particles, and content of elements were analyzed by SEM-EDS. Results of contact angles, degradation of methylene blue and red wine show that the self-cleaning performances of fabrics treated by Ti O2 sols are dramatically improved.Ag(silver), La(lanthanum), N(nitrogen), and Y(yttrium) doped nano-Ti O2 sols of aqueous system were prepared, characterized, and used to treat silk fabric. Absorbance edge of doped sols, particles in UV-Vis spectra appear red-shift, meaning good photo catalytic activities. Chemical status, concentration of atoms on fiber surface that treated by sols were examined by X-ray photoelectron spectrum(XPS), while different smoothness and agglomeration were also observed by SEM. Changing of contact angles between fiber and water droplet under UV radiation is in accordance with Stirling model. Adsorption equilibrium of Freundlich model, pseudo-second kinetic model of MB adsorption on B.mori silk, and pseudo-first model of degradation of MB under UV radiation were also discussed.Combination of nano-Ti O2 sols and cold oxygen plasma in processing B. mori silk and their influence on fibers were studied. Sequences and parameters in processing procedures can affect the amounts of hydroxyl groups, smoothness, and crystallinity index of fibers. Organic-inorganic hybrided blends are formed by introducing titanate coupling agents, which decreases the fiber smoothness with elevated thermal performance. Either applying sols before plasma treatment or curing at lower temperature is beneficial to obtain higher crystallinity index and less stable thermal abilities.Preparation, modification, and application of Cd Se, Zn S, and Ag2 S quantum dots(QDs) on Ti O2 sols pretreated silk fabrics to improve the self-cleaning abilities were investigated. Photoluminescence(PL) intensify of Cd Se decreases in polarized solvent or at elevated p H value of the medium. Integrating QDs with Ti O2 sols makes the red-shift of absorbance edge in UVvis spectra. Increasing stabilities of Zn S and Ag2 S QDs modified by 2-Thioglycolic acid(TGA) and(3-Mercaptopropyl) trimethoxysilane(MPS) were observed while elevated p H value will result blue-shift of absorbance edge. Zinc blende of as-prepared Zn S, acanthite of Ag2 S were demonstrated by XRD. Much purer phase of Zn S and Ag2 S modified by MPS, and the resulting much smoothness of fiber surfaces were also observed. Concentration of atoms on fiber surfaces calculating from XPS analysis show that QDs are fixed on fiber or Ti O2 nano-particles, which promotes the decreases of contact angles under UV radiation and increases of decomposition velocities of MB and red wine stain. The adsorption characterization of MB on QDs treated silks is in accordance with pseudo-second kinetic model, Freundlich model of adsorption equilibrium, and pseudo-first kinetic model of degradation of MB.