【摘要】 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 。更多还原

【Abstract】 Nano porous SiO 2 aerogel insulation were prepared via sol gel process using tetraethoxysilane (TEOS) as the precursor and followed by ethanol supercritical drying TEM, SEM and pore size distribution techniques were used to characterize the morphology and pore structure of the silica aerogels The thermal conductivity measurement of the silica aerogels was determined using the transient hot wire technique The results show that the pore size is 5～70 nm, the average pore size (BJH) is about 20 nm, the size of the particles is 5～10nm while the thermal conductivity of the silica aerogel (100kgm -3 ) is 0 0125 Wm -1 K -1 at room temperature and 1 atm更多还原