Ito Transparent Insulation Film Preparation, Characterization And Performance Study

As more and more attention has been paid to the energy conservation and environmental protection, the building glass with higher transparency and better insulating performance is required. Nanoscaled indium tin oxide (ITO) is an ideal transparent and heat-insulating material due to its high transparency in visible light zone and effective infrared-insulating performance. The transparent and heat insulating films made from nano-ITO can effectively improve the heat-insulating performance of the conventional glass. In addition, the fabrication of ITO films by adding ITO powder into the basic coating is simple and low costed. It is expected that this kind of films has high practical application value and wide market prospects.The ITO ethanol slurry was prepared by dispersing ITO powder into ethanol solution. The effects of the dispersing agents, the content of ITO, the dispersing methods, and the dispersing time on the stability of slurry were discussed. The basic coating was prepared to improve the mechanical performance of ITO films. Nano-SiO2 was surface modified to be lipophilic by dimethyl dichlorosilane. The results showed that the surface modified particles had a uniform distribution in size and well dispersed. And the average size of SiO₂ particles in coatings was about 20 nm. The basic coating was fabricated with modified SiO₂ and acrylic resin as starting materials.The heat insulating coating with high transparent performance was obtained by mixing the ITO ethanol slurry with the basic coating. Then, the transparent and heat-insulating ITO film was prepared by spin coating on the substrate. The dispersion stability and coating performance of the coating were investigated. When the ITO ethanol slurry was mixed with basic coating by a volume ratio of 1:4, the prepared coating showed good dispersion stability. The results indicated the heat-insulating coating had the best dispersity and the prepared films possessed a good mechanical performance when the content of nano- SiO₂ particle was 2% in the basic coating and the heat-insulating coating was dispersed by ultrasonic treating for 30min then further treated by ball-milling dispersion for 24 hours.The results of the mechanical performance, optical properties, and microstructure analysis indicated that the transparent and insulation ITO film showed good comprehensive mechanical performance and high spectral selectivity. The visible light transmittance and the infrared light transmittance of the film were 90% and 50%, respectively. TEM analysis of the coating indicated that the particle size of ITO was about 50 nm and in a narrow distribution.The heat insulating performance of the coatings was assessed in a lab-constructed equipment. The results indicated that the ITO film showed good heat-insulating efficiency. The temperature of the chamber loaded with the insulating glass was lower than that of the one with the conventional glass for 12.2℃under the irradiation of iodine-tungsten lamp.