Si02气凝胶微球的制备及表征

以正硅酸乙酯（TEOS）为先驱体制备硅溶胶，再以硅油为分散介质，在吐温80为乳化剂的油相与SiO2溶胶为水相的乳化体系中，应用雾化法和乳液成球技术制备微米级SiO2凝胶小球，然后，通过超临界CO2干燥技术制备微米级siO2气凝胶小球，用光学显微镜、SEM、红外光谱（FT—IR）及cBET技术对其表征，结果表明，微米及SiO2气凝胶小球表观粒径较为均匀，平均粒径约为30μm，密度为216kg／m2，平均孔径6．72nm，BET比表面积为802．35m2／g，孔体积为1．15cm3／g，是一种具有典型气凝胶结构的微粒状轻质纳米多孔材料。

Preparation and Characterization of SiO2 Areogel Microsphere

Silica sol were fabricated by using tetraethyl orthosilicate （TEOS） as precursor,then the as-prepared silica sol were formed SiO2 areogel microspheres in the emulsion composed of oil phase of silicone oil and aqueous phase of silica alcosol with Tween 80 surfactant, by atomizing and emulsion method. In order to produce SiO2 areogel microspheres,the silica alcogel microspheres were dried at supercritical CO2 technique. The resultant silica aerogel microspheres were characterized by optical microscope,SEM,Fourier transform infrared spectroscopy （FT-IR） and BET technique. The results show that the average spherical diameter of the prepared silica aerogel microspheres was about 30 μm,the density of 216 kg/m3,average pore diameter of 6.72 nm,specific surface area of 802.35 m2/g and cumulative volume of 1.15 cm3/g. Therefore, SiO2 areogel microspheres are a novel kind of nanoporous structural material.