Study On Preparation And Performance Of Transparent And Heat-insulating Glass Nano-coating

As the society enhances requirements for energy sources and environments ceaselessly, heat-insulating glass that can be used for different requirements becomes people's demand at large. The existing heat-insulating glass has the defects on faulty performance, complex process and high cost. Having high transparency in visible light and effective infrared-insulating performance, nano-meter tin antimony oxide (ATO) is an ideal heat-insulating material. The preparation of transparent and heat-insulating coating made from nano-ATO can solve these problems, and it has the advantages of more simple process and lower cost than those of the same class products. So this kind of coating has extremely high practical application value and wide market prospects.The dispersion behaviors of nano-ATO in aqueous system were studied in this paper firstly. Influence of pH value, type and content of dispersants, different dispersing methods and processing parameters on the dispersion stability was discussed. The results indicated that the iso-electric point lied the place that pH=4.27. The dispersion stability was enhanced remarkably in alkaline system. The optimum dispersant and its content in dispersion system was a kind of anionic macromolecule dispersant and 2% of the weight of ATO composite. Influences of different dispersing methods and processing parameters on the dispersion stability were compared in this paper too. Talking about single dispersing method, milling and high-speed dispersion were more effective than ultrasonic dispersion. The same particle sizes and shorter dealing time could be obtained when the system was dispersed by two-phases milling method. Diameters of most nano-ATO particles in the slurry were within 100nm dispersed using the optimum dispersant and the dispersing process.A transparent coating with good heat-insulation property has been prepared based on nano-ATO slurry and aqueous polyurethane mixing with thickening agent and other assistant agents. Result of the determination under self-made devices of heat-insulation effect testing indicated that the coatings had good heat-insulation effects. The smooth temperature difference of the air inside the box was 6°C between the clean sample and sample with ratio of pigment to base is 1/5. The discussion on mechanism of heat-insulation indicated that heat-insulation effect was the coordination of absorption and reflection. The coatings had remarkable solar spectrum selectivity, which could transmit visible lights and insulate near-infrared radiation. For coatings with ratio of pigment to base is 1/5., the average transmittance of whole solar spectrum was 65%, which was down to 40% in near-infrared zone. SEM analysis on the coatings indicated that the size of ATO composites in coatings were whin100nm and the surface is smooth.