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以正硅酸四乙酯为硅源， 通过溶胶－凝胶及超临界干燥过程制备了 ＳｉＯ２ 气凝胶。用透射电镜、扫描电镜以及孔径分布仪对其结构进行了表征， 并用稳态热线法对其热学特性进行了测试。结果表明： ＳｉＯ２ 气凝胶的孔洞大小分布在 ５～７０ｎｍ ， 峰值在 ２０ｎｍ 附近， 组成网络的胶体颗粒为 ５～１０ｎｍ ； 热学测试结果显示ＳｉＯ２ 气凝胶 （１００ｋｇｍ － ３ ） 的热导率在常温常压下为 ０．０１２５Ｗｍ － １ Ｋ－ １ 。
SiO2 aerogels were prepared by sol-gel and supercritical drying using tetraethyl orthosilicate as silicon source. Its structure was characterized by transmission electron microscopy, scanning electron microscopy and pore size distribution analyzer, and its thermal properties were tested by steady-state hot-wire method. The results show that the pore size of SiO2 aerogels is in the range of 5 ~ 70nm and the peak value is in the vicinity of 20nm, and the colloidal particles of the network are 5 ~ 10nm. The thermal test results show that the thermal conductivity of SiO2 aerogels (100kgm - 3) Atmospheric pressure is 0.0125Wm - 1 K-1.