| As the society pays more and more attention to problems of energy resources andthe environment, higher and higher requirements have been put forward to transparentand heat insulating performance of glass. Although the transparency of ordinary glassis considerably high, it can hardly insulate the infrared radiation, which results inenormous energy loss on occasions when insulation from heat radiation is necessary.Currently existing heat insulation glass has these defects, generally weighing down onperformance or production cost. Having high transparency in visible light andeffective infrared-insulating performance, nano-metered indium tin oxide (ITO) is anideal transparent and heat-insulating material. The preparation of transparent and heatinsulating coatings made from nano-ITO can solve these problems. In addition, it hasadvantages like low cost and a simplified production process. So this kind of coatinghas very high practical application values and wide market prospects. The dispersion behaviors of nano-ITO in an aqueous system are studied in thispaper firstly. The Influence of PH value, type and content of dispersants, dispersionmedium, processing parameters, and different dispersing methods for dispersionstability results are discussed. These indicate that the isoelectric point determined inwater is 7-8. The dispersion stability improves when the PH value rises above orbelow this value. The optimum dispersant and its content in the dispersion system isEP, and 15% of the weight of nano particles. The maximum improvements ofdispersion stability are acquired when 50% of ethanol by volume is added to thedispersion system. The influence of different dispersing methods and processingparameters on the dispersion stability are compared. The ultrasonic dispersion methodis more effective than milling and high-speed dispersion methods. The combination ofboth high-speed and ultrasonic dispersion methods can improve the dispersing effectsslightly more than ultrasonic dispersion, which can acquire a nano ITO slurry havingaverage diameter of 100nm and a narrow particle size distribution. Transparent and heat insulating coating of high performance is prepared by iABSTRACTadding aqueous polyurethane film-forming agent to aqueous slurry of nano ITO, andadjusting the cosolvent and PH value of the coating system. By looking at the resultsof the coating's mechanical and optical performance, including the SEM analysis, wecan draw the conclusion that 0.017 is near to the actual CPVC value of that coating,and it has a good comprehensive mechanical performance. The coating hasremarkable solar spectrum selectivity that can transmit visible light and insulateinfrared radiation. For the coating which has a PVC value of 0.017, the visible lighttransmittance is 86.73%, and infrared radiation insulation is 48.6%. The solar directtransmittance is 72.04% and 75.37% respectively when the atmosphere quality is 1and 2. That is to say, 27.96% and 24.63% of the heat coming from solar radiation isinsulated respectively. SEM analysis of the coatings indicates that the distribution ofITO in coatings is almost homogeneous. The heat insulating effects of the coating isdetermined by self-made equipment. Results indicate that the coating has obvious heatinsulating effects, which have a temperature difference of 6-13℃ between the heatinsulating and ordinary glass under iodine-tungsten lamp.
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