Research On Multi-functional Composite Properties Nano-thin Film Coated On Glass

Rapid population growth, severe shortage of energy and continued deterioration of the environment have been the biggest problems for humanity. They have threatened the sustainable development of society and human's long-term development. These require the material industry to take the way of conservation of resources utilization, reduced energy consumption and harmonious coexistence between man and nature. TiO₂ is the just "ecological environment material" satisfying these requirements.Because of the superhydrophilicity and superlipophilicity of TiO₂, it has an effect of anti-fog. Meanwhile, TiO₂ has very good photocatalysis decomposing toxic organics and has been widely used to deal with water pollutants and air pollution. It also can be used as antiseptic deodorization in wall, water dispensers and indoor furniture surface. Thus, depositing this material on glass can make glass anti-fog and Self-cleaning. In addition, because the refractive index of TiO₂ is larger , compositing it with high reflectivity metal film like Ag, Cr can effectively reduce the transmittance of the far-infrared and ultraviolet light to make the inside of the building cooler in summer and warmer in winter.This paper studies the preparing of TiO₂ thin films by DC magnetron sputtering in detail and discusses the impact of each parameter on the photocatalysis of TiO₂ film. By XRD analysis, when the sputtering pressure is very low, we can know the oxygen is too little to produce TiO₂ but TiO, Ti2O3 substances.When the sputtering pressure is 1.0 Pa , it can produce anatase TiO₂ that has very good photocatalysis. When sputtering pressure is 1.0 Pa and the oxygen partial pressure is very high, accordingly, the oxygen vacanciesmay is too little to improve the photocatalysis. So experiments have found that when the pressure is 0.2, the photocatalysis of TiO₂ is the best. Meanwhile, heat treatment can improve the crystallization of TiO₂ and effectively improve the photocatalysis of TiO₂. Appropriately increasing the substrate's temperature to improve the crystallization of TiO₂ is beneficial to the improvement of photocatalysis. However, if temperature is exorbitant , it may increase the particle size of TiO₂ and cause blueshift of the threshold value of transmissivity influencing the photocatalysis. Research shows that when the substrate's temperature is 300℃,the photocatalysis is the best.The next research is about the preparing of TiO₂/SiO₂ anti-fog and self-cleaning thin film by reactive magnetron sputtering. We discusse how do different processing technologies affect composite materials'photocatalysis and hydrophilicity. By Contact Angle meter, we find that the contact Angle between water and glass is zero after sputtering a layer of SiO₂ thin film on the surface of TiO₂ and water droplets can quickly unfolding, thus greatly improving the membrane's hydrophilicity. Thereby, this composite material has very good performance of anti-fog. In addition, when oxygen partial pressure is high, the prepared composite material has high photocatalysis while has super hydrophilicity. Thus, it aslo have a good function of self-cleaning. In order to further improve the composite film's photocatalysis, we attempt to take techniques, like DC magnetron sputtering and anodic oxidation, to synthesize TiO₂ nanotubes. By the photocatalytic test, we had found that TiO₂ nanotubes can greatly improve its photocatalysis. Meanwhile, we have done some modified experiments by depositing Bi2S3 on the surface of TiO₂ nanotubes. Experiments show that that can also improve it's photocatalysis and it's degradation rate can reach 70.5% after three hours.The last part low-e multilayers are studied. Through the spectrum analysis and thermal insulation testing experiment, wo learn that when the thickness of TiO₂, Ag and Si3N4 is respectively 54nm, 13nm and 53nm, low-e multilayers have very low emissivity and their transmissivity is under 10% at 2500nm ; As well as metal Ag layer, the transition layer of low-e multilayers Ti need preparing at room temperaturee, and the transition layer can promote the silver particles connecting as soon as possible and protect them from corrosion in high temperature. So Ti is an essential layer. The passivation layers can be NiCrOx or NiCr and they play almost the same part.