玻璃纤维增韧SiO2气凝胶复合材料的制备及隔热性能  

Synthesis and Heat Insulation Performance of Glass Fiber Reinforced SiO_2 Aerogel Composites

作　　者：石小靖 张瑞芳[1] 何松[1] 李治[1] 曹卫[1] 程旭东[1] 

机构地区：[1]中国科学技术大学,火灾科学国家重点实验室,合肥230027

出　　处：《硅酸盐学报》2016年第1期129-135,共7页Journal of The Chinese Ceramic Society

基　　金：中央高校基本科研业务费专项资金项目(WK2320000032)

摘　　要：采用蓬松处理后的玻璃纤维薄层为增强相,通过溶胶-凝胶法常压干燥条件下制备疏水性的SiO_2气凝胶复合隔热材料。研究了水与硅的摩尔比和玻璃纤维添加量对复合材料导热性能的影响。结果表明:前驱体液中水与硅的摩尔比为3:1时,复合材料中SiO_2气凝胶平均纳米孔径为8.160 nm,材料的密度为0.142 g/cm^3,孔隙率为88.03%,导热系数低达0.023 2 W/(m·K)。随着样品中纤维薄层含量的增加,复合材料的导热系数近似线性增长。考虑材料的成型条件,最优的纤维添加量为16%,材料的抗弯强度为0.533 MPa,抗压强度为29.59 kPa(25%形变)。与传统玻璃纤维增韧气凝胶复合材料相比,新材料的纤维添加量降低,材料密度更小(0.13~0.16 g/cm^3),导热更低(0.023~0.027 W/(m·K))。Glass fibers were prepared by a fiber carding machine, and subsequently the glass fiber films were added into a silica sol as a skeleton to support the aerogel matrix. The hydrophobic insulated SiO2 aerogel composites were prepared in ambient pressure via a sol-gel method. The influences of fiber content and mole ratio of water to silicon on the thermal conductivity of composites were investigated. The results indicate that the average pore size of the SiO2 aerogel composites is 8.610 nm when the mole ratio of water to Si precursor is 3：1. The density and porosity of the composites are 0.142 g/cm3 and 88%, respectively. The thermal conductivity of the composites is 0.023 2 W/（m＇K）. The thermal conductivity of the composites increases with the increase of fiber content. The optimum fiber content is 16%. The flexural strength and compressive strength of the composites are 0.533 MP and 29.59 kPa （25% strain）, respectively. Compared to the conventional fiber-reinforced silica aerogel composites, the composite with glass fiber films prepared is superior. The density of the composite decreases to 0.13-0.16g/cm3 and the heat conductivity decreases to 0.023--0.027 W/（m·K） when the glass fiber content decreases enormously.

关 键 词：二氧化硅气凝胶 玻璃纤维 隔热材料 

分 类 号：O684[理学—化学]