Study On Preparation And Performance Of Tungsten Bronze Super-hydrophobic Transparent Thermal Insulation Coating

With the rapid development of social science and technology,the country pays more and more attention to energy and environmental issues.In order to maintain the harmonious symbiosis between man,society and the ecological environment,energy saving and consumption reduction has always been one of the hot spots of people's attention and research.The large-scale use of glass structures in modern buildings tends to increase the energy consumption of air-conditioning and refrigeration in summer.Improving the thermal insulation capacity of building glass is of great significance to the energy saving and consumption reduction of buildings.Compared with other nanometre transparent heat-insulating materials,tungsten bronze material has excellent visible light transmittance and near-infrared blocking performance,making its application in the field of architectural glass energy saving more promising.Although the currently studied tungsten bronze coating has a certain degree of transparency and heat insulation performance,because the architectural glass is exposed to the outdoors for many years during use,dust or other pollutants in the air tend to accumulate on the surface of the coating,resulting in the transparency of the coating.The thermal insulation performance is reduced,so the super-hydrophobic,self-cleaning and friction resistance properties of the tungsten bronze transparent thermal insulation coating are particularly important.In this thesis,cesium tungsten bronze and sodium tungsten bronze nanometre materials were prepared by solvothermal method.Using this as the substrate,a high-roughness micro-nanometre composite structure was constructed through hydrophobic modification and addition of Silicon dioxide nanometre.The oily coating with super-hydrophobic transparent heat insulation was prepared by organic-inorganic composite method.The influence of the molar ratio of raw materials,the reaction time,and the concentration of oleic acid in the preparation process of tungsten bronze on the composition and morphology of tungsten bronze and the transparent and thermal insulation properties of the film are studied;The influence of super-hydrophobic,abrasion resistance and self-cleaning performance.The specific research content includes the following parts:(1)Cesium tungsten bronze(Cs_0.3WO₃)was prepared by solvothermal method.The influence of the molar ratio of cesium to tungsten,the reaction time and the concentration of oleic acid in the reactants on the phase and morphology of cesium tungsten bronze and the transparent thermal insulation properties of the film were studied.When the Cs/W molar ratio is 5:10,the reaction time is 8h,and the oleic acid concentration is 10%,Cs_0.3WO₃exhibits high visible light transmittance and near-infrared blocking rate,and the near-infrared blocking rate of its coating The visible light transmittance is 89.4%,and the visible light transmittance is 65.2%.Compared with the blank coating,under the same conditions,the internal temperature can be lowered by 9.7?,and the heat insulation effect is remarkable.(2)Sodium tungsten bronze(Na_0.3WO₃)was prepared by solvothermal method,and the influence of sodium tungsten molar ratio,reaction time and oleic acid concentration on the composition,morphology and transparent thermal insulation properties of the film was explored.When the molar ratio of Na/W is 5:10,the reaction time is 8h,and the concentration of oleic acid is 10%,the obtained Na_0.3WO₃exhibits better visible light transmittance and near-infrared blocking rate.The near-infrared blocking rate is 73.4%,and the visible light transmittance is 64.9%.Compared with the blank coating,under the same conditions,the internal temperature is lowered by 6.9?,and the heat insulation effect is inferior to that of the cesium tungsten bronze film.(3)The dispersion stability of the modified tungsten bronze powders in oily solvents and the effects of the mass ratio of Si O₂to tungsten bronze powders on the hydrophobic property,mechanical wear resistance and transparent heat insulation properties of the coating were studied by organic-inorganic complex method.When the total powder content is 12wt%,the mass ratio between the modified tungsten bronze powder and nano-Si O₂increases from 12:0 to 0:12.With the increase of Si O₂,the contact Angle(CA)of the coating surface increases first and then decreases,and the rolling Angle(SA)decreases first and then increases.When the hardness of the coating increases,the wear resistance decreases.When the ratio of modified tungsten bronze powder to nanometre silica is between 4:8 and 8:4,the super-hydrophobic property can be achieved,and the roughness of the corresponding coating is also high.When the mass ratio of Si O₂and Cs_0.3WO₃(or Na_0.3WO₃)is 4:8,the Ca value of the coating is 169.8°and 168.7°,the SA value is 4.4°and 4.6°,the near-infrared blocking rate of the coating is 82.8%and 64.2%,and the transmittance of visible light is 60%,respectively.Achieving better transparent heat insulation and super-hydrophobic performance.