SiO_2气凝胶小球的制备及表征

Preparation and characterization of SiO_2 aerogel balls

以国产硅溶胶为原料,通过滴液成球法和非超临界干燥工艺制备SiO2气凝胶小球,并对其结构进行了表征。研究结果表明,该SiO2气凝胶小球是由粒径为10nm左右的SiO2纳米粒子构成的轻质多孔材料,其比表面积高达271.89m2/g,孔隙率在90%左右,孔分布集中在10～30nm,密度约300kg/m3。气凝胶小球的直径在1～5mm范围内精确可控。

SiO_2 aerogel balls have been prepared from silica sols by adopting ball-dropping following by non-supercritical drying technique,and their structural features have been characterized. It is found that the aerogel balls, which are made up of uniform spherical nanoparticles with diameters of about 10nm, are of coherent network structural lightweight materials with porosity as high as 90%. The diameters of the pore are in the range of 10～30nm,and the density of the aerogel balls is about 300kg/m^(3), while the specific surface area of them is about 271.89m^2/g. The diameters of the aerogel balls can be well controlled in the range of 1～5mm.