块状纳米孔超级绝热材料的制备与表征  

Preparation and characterization of monolithic super thermal insulation with nanoporous structures

作　　者：杨海龙[1] 倪文[1] 肖晋宜[1] 郑骥[1] 赵雪娜[1] 

机构地区：[1]北京科技大学土木与环境工程学院,北京100083

出　　处：《化工新型材料》2006年第9期65-67,71,共4页New Chemical Materials

基　　金：国家"863"高技术研究发展计划资助项目(编号:2003AA302610)

摘　　要：以正硅酸乙酯为硅源，采用两步溶胶-凝胶法结合超临界干燥技术制备出了块状无裂纹SiO2气凝胶，体积密度在50kg·m^-3和300kg·m^-3之间，样品尺寸约为300mm×300mm×50mm。热学测试表明，常温常压下体积密度大约为100kg·m^-3的样品导热系数为0．020W／m·K，并采用XRD、SAXS、BJH和SEM等其他方法对典型样品（100kg·m^-3）进行了测试。测试结果表明，SiO2气凝胶是非晶态的，并且具有纳米多孔结构（骨架颗粒平均粒径为6．8nm，孔径主要集中在10-20nm范围内，而且所有孔径都在70nm以内）。因而可作为具有一定潜在应用价值的块状纳米孔超级绝热材料。Monolithic silica aerogels of crackfree which were from tetraethoxysilane were prepared by two-step sol-gel process and supercritical drying technique, their densities are in the range of 50- 300kg · m^-3 and their sizes are about 300 × 300 × 50mm^3. The thermal conductivity measurement of the material（100 kg · m^-3） is 0. 020 W/m · K at normal temperature and pressure, and is also tested by using XRD, SAXS, BJH, SEM and some other experimental techniques. The test results showed that the silica aerogel was non-crystalline,and it had nanosized porous structure （the mean diameter of skeletal particles was 6.8nm, a fairly uniform pore size distribution was in the range of 10-20nm and all pores＇ size is less than 70nm）. So they can be used currently and potentially as nonporous superthermal insulation materials.

关 键 词：SIO2 气凝胶 超级绝热 纳米孔 

分 类 号：TB383.1[一般工业技术—材料科学与工程]