自清洁、防雾聚氨酯-SiO2复合超亲水透明涂层的制备与表征

玻璃幕墙具有难清洁、易起雾等缺点，增加了墙体维护的成本。以水性聚氨酯（PU）、亲水型纳米SiO₂、正硅酸乙酯（TEOS）和乙醇为基本原料，采用喷涂工艺，将配置好的PU-SiO₂涂层溶液喷涂在玻璃幕墙上，常温固化后即可得到具有良好耐磨性、防雾的PU-SiO₂透明涂层。利用SEM对PU-SiO₂涂层表面形貌进行了表征并通过对比实验探究了表面润湿性的成因，分析了PU-SiO₂涂层具有超亲水特性原理。耐磨性和防雾性测试结果表明:PU-SiO₂涂层最大可承受约为26 kPa的压强并具有良好的防雾特性。紫外可见分光光度计测试结果表明:PU-SiO₂涂层具有良好的透明性。户外放置实验表明:PU-SiO₂涂层具有良好的耐候性。该方法解决了复杂工序问题和环保问题，可直接用于现有建筑物的玻璃幕墙表面。 

Preparation and characterization of polyurethane-SiO2 composite super-hydrophilic transparent coating with self-cleaning and anti-fog

Glass curtain is foggy and difficult to clean,which increases the cost of wall maintenance.The waterborne polyurethane(PU),hydrophilic SiO2,tetraethyl orthosilicate(TEOS)and ethanol were used as basic materials,and the PU-SiO2 coatings were sprayed on glass curtain wall by spraying process.After curing at room temperature,a transparent PU-SiO2 coating with good wear resistance and fog resistance could be obtained.The surface morphology of the PU-SiO2 coatings was characterized by SEM and the causes of surface wettability were explored through comparative experiments.The principle of superhydrophilicity of the PU-SiO2 coatings was analyzed.The results of wear resistance and fog resistance test show that the PU-SiO2 coating can withstand the maximum pressure of about 26 kPa and has good fog resistance.Ultraviolet-visible spectrophotometer test results show that the PU-SiO2 coating has good transparency.The outdoor experiment shows that the PU-SiO2 coating has good weatherability.The method used in this paper solves the problems of complex process and environmental protection of existing methods,and can be directly applied to the glass curtain wall surface of existing buildings.