疏水型二氧化硅气凝胶复合材料的制备及其性能

Preparation and properties of hydrophobic silica aerogel composites

为有效改善二氧化硅气凝胶的热防护性能,采用溶胶-凝胶法合成疏水型二氧化硅气凝胶复合材料。利用红外光谱、扫描电镜和比表面积等对其进行表征,测试并分析其疏水性、热稳定性能、整体热防护性能及阻燃性。结果表明:复合材料在614.0℃时开始出现明显失重,其比表面积为331.27 m^(2)/g,接触角为142.59°;且其热防护性能值为(797.78±32.98)kW·s/m^(2),辐射热传导指数和对流热传导指数分别为19.1 s和11.4 s;阻燃性能测试结果显示试样的损毁长度为20 mm,未出现熔融、滴落现象。

In order to improve the thermal protection performance of silica aerogel effectively,the silica aerogel composite was synthesized by sol-gel method.The structure of composite was characterized by infrared spectrum,scanning electron microscope and BET analysis.The hydrophobicity,thermal stability,overall thermal protection and flame retardancy of the composite were tested.The results show that the composite begins to lose weight rapidly at 614.0℃,its specific surface area is 331.27 m^(2)/g,and the contact angle is 142.59°.The thermal protection performance,radiative heat and convective heat conduction index of the composite are(797.78±32.98)kW·s/m^(2),19.1、11.4 s,respectively.Flame retardant test shows that the damage length of the sample is 20 mm,and there is no melting or dripping phenomenon of the sample.