The Preparation And Heat-insulation Properties Of Transparent Nanocomposite As Glass Coating For Architectural Energy-saving

In recent years, the large windows and glass curtain wall are widely used in the building and vehicle. The application of large windows and glass curtain wall leads to the increasing of energy consumption in building or vehicle, such as increasing the usage of air-condition in summer and heater in winter. Investigation has shown that about 50% of energy consumption is loosed through doors and windows of building. For saving the energy consumption in building, solar filters have been used around the world as a coating for architectural glass. Generally, such filters should have high shielding efficiency for near-infrared (NIR) and high transmittance for visible light (Vis). These properties would contribute low heat gain and undiminished luminosity inside the building, respectively.Antimony-doped SnO2 (ATO), aluminum-doped ZnO (AZO), gallium-doped ZnO (GZO) has shown good visible light transmittance and excellent infrared radiation shielding efficiency. Furthermore, the cost of ATO, GZO and AZO is far below the cost of traditional solar filter Sn-doped In2O3 (ITO). These materials have great potential as solar filter to replace ITO. In this thesis, ATO, GZO and AZO nanoparticles were prepared with a polymer-pyrolysis method and then transparent thermal insulation coating were prepared by mixing the obtained nanoparticles with transparent epoxy resin. The major results are presented as follows:(1) ATO nanoparticles with the different Sb content were successfully prepared via a polymer-pyrolysis method for the first time. With the increasing of the Sb content, the size of ATO nanoparticles is decreased. The particle size of ATO with 15at% Sb is 25nm. Moreover, the conductivity of SnO2 is significantly improved with the Sb doping. The resistivity of the 10~13at% Sb-doped SnO2 is decreased by more than three orders compared with the pure SnO2.(2) GZO and AZO nanoparticles also were prepared via the polymer-pyrolysis method. With the increasing of Ga and Al doping content, the resistance of GZO and AZO both decreases at lower doping content, and reaches the optimal electrical conductivity with 4at% Ga and 8at% Al for GZO and AZO, respectively. In addition, with high temperature annealing under H2 atmosphere, the resistivity of the GZO nanoparticles is decreased three orders in magnitude compared with non-treatment GZO nanoparticles.(3) Transparent ATO/epoxy, GZO/epoxy and AZO/epoxy thermal insulation coating were prepared by mixing ATO, GZO and AZO nanoparticles with transparent epoxy resin, the optical and heat insulation properties of the coating also have been studied.(4) The UV-Vis-NIR spectra reveal that the coatings with higher filler content possess good infrared shielding efficiency and bad visible light transmittance. For the three kind of thermal insulating coating, ATO/epoxy coating has the best visible light transmittance. GZO/epoxy coating shows the best infrared shielding efficiency, and for AZO/epoxy displays the best performance with the balance of 50% visible light transmittance and up to 75% infrared shielding efficiency.(5) The heat insulation property investigation reveal that ATO/epoxy, GZO/epoxy and AZO/epoxy all have excellent adiabatic performance. For the epoxy coating with the same filler content, GZO nanoparticles show the best heat-insulation performance compared with ATO and AZO. In the building environment simulation test, the highest chamber temperature difference between GZO/epoxy coated glasses and control glass sheet is 12℃.