| Nano-Ti O2 has been widely used in many fields due to the surface effect, small size effect, quantum effect and macroscopic quantum tunneling effect and other characteristics, but also possesses excellent chemical stability, high surface area, non-toxic, low cost. Nano-Ti O2 may give the fabric UV resistant, anti-bacterial, VOC degradation and self-cleaning function if it is applied to textiles. However, nano-Ti O2 has some defects, such as wide band gap, photogenerated carrier recombination rate and others which limited the scope of its application, and the industrial preparation of Ti O2 at present require high-temperature calcination to obtain good crystalline powder or film, this limits the application of Ti O2 to flexible textile material.This article prepared modified nano-Ti O2 to solve the defect of Ti O2 photocatalytic material. We deposited the noble metals Ag on its surface, as well as metal(Fe, La) or non-metallic(N) doped nano-Ti O2, and using these methods to improve nano-Ti O2 quantum yield and broaden the range of light response, improve the photocatalytic activity; meanwhile, the article also research deeply the thermal crystallization treatment, dispersion, crystallization and fastness between nanoparticles and fiber when nano-Ti O2 is applied to multifunctional composite textile at low temperatures. The main contents include:Preparation and Properties of Ag/Ti O2 Nanocrystals at Low Temperature. Preparing Ag/Ti O2 by sol-gel method at low temperature, and discussing the reaction mechanism and the reaction sequence of DEA as a complexing agent and an auxiliary reducing agent and analyze the effect of reaction conditions on the preparation process of Ag/Ti O2. The results showed that: the prepared nano-Ti O2 were anatase phase with high crystallinity, crystallite size is 6-9nm, Ag clusters distribution uniformly on the surface of Ti O2. Schottky barrier is formed between Ag clusters and the Ti O2 particle with a strong electron-accepting and passing ability, it can effectively inhibit the Ti O2 bulk electron-hole complex and obviously improved photocatalytic properties of Ti O2. Performance tests show that the photocatalytic effect of 3%Ag/Ti O2 is most excellent, and the resonance absorption of Ag nanoparticles on the surface of Ti O2 making the nano-Ti O2 also has some of the photocatalytic effect under the visible region. Meanwhile, Ag/Ti O2 powder has the dual antibacterial effect of Ag and photocatalytic of Ti O2, the antibacterial properties of Ti O2 has also been improved with increasing Ag loading.Preparation and Properties of Dual Collaborative Modified Nano-Ti O2 based on Ag loading Ti O2. To further enhance the photocatalytic properties of Ti O2, Doping Fe, N and La as common doping elements on the basis of Ag/Ti O2 directly prepared by sol-gel method according to the mechanism of improving quantum yield, inhibition of photo-generated electrons-complex holes and broaden the light response range, and further improve the photocatalytic properties of nano-Ti O2 using the synergies between the dopant ions and Ag, and the use of hybrid orbital theory and research the reason that the increasement of photocatalysis, light response range and the useful ability of doped nano-Ti O2. The research shows that: It may be introduce defection or change the degree of crystallinity by doping a metal or non-metal ions in the Ti O2 lattice which narrowed the band gap of the doped Ti O2 and the impact recombination of photo-generated holes and electrons, and the visible light can also stimulate their photocatalytic ability, broaden the scope of the optical response of Ti O2, at the same time further improve the photocatalytic activity of nano-Ti O2 useing synergy between doping element and Ag. Compared with single doped or undoped Ti O2, Doped Nanocrystalline Ti O2 has a very good degradation effect of methylene blue under the UV and visible light, and photo-catalytic activity of Ti O2 after doping depended on the features and density of doping ions, and the synergy between doping element and Ag.Dispersion, Growth Control and Its application in multi-functional Finishing of Cotton Fabric of Nano-Ti O2. The low-temperature prepared modified nano-Ti O2 hydrosols were applied on cotton fabrics for multi-function. The effects of different treatment methods on growth control and dispersive uniformity of nano Ti O2 were analyzed, and the treated cotton fabrics had excellent performances like anti-UV, anti-bacteria, self-cleaning, degrading VOC, etc. The research showed that the high pressure steaming treatment could control the growth of Ti O2 and hydrolysis reaction without dispersant, and the nano particles could be uniformly dispersed on cotton fabrics. Compared with hydrothermal technology, the crystallization intensity of nano Ti O2 particles prepared by high pressure steaming treatment were much higher, and the crystalline intensity similar to the conventional hydrothermal process. The nano particles could be firmly bonded with fiber without obvious influence on the fabric whiteness and breaking strength. |
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