Preparation of silica aerogel from rice hull ash by drying at atmospheric pressure
Preparation of silica aerogel from rice hull ash by drying at atmospheric pressure
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DOI：
10.1016/j.matchemphys.2008.05.066
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发表时间：
2008-12
影响因子：
4.6
通讯作者：
Ting Li;Tao Wang
中科院分区：
文献类型：
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作者：
Ting Li;Tao Wang
二氧化硅气凝胶通过溶胶-凝胶工艺制备，然后在大气压和40°C下干燥工艺。硅源为富含硅的农业废弃物稻壳船体灰。用氢氧化钠溶液萃取稻壳船体灰以得到硅酸钠溶液。该溶液用硫酸溶液中和形成二氧化硅水溶胶，立即加入适量的正硅酸乙酯（TEOS），然后凝胶化成凝胶。将老化的凝胶依次用水和乙醇洗涤，最后在大气压下干燥。用透射电子显微镜（TEM）和BET（比表面积）测试对所制备的材料进行了表征。制备的材料比表面积高达500 m2/g，堆密度为0.33g/cm 3。所制备的材料内部的孔的直径在5 - 60 nm之间。
The silica aerogel was prepared by a sol–gel process followed the drying process at atmospheric pressure and 40°C. The silicon source was the rice hull ash, which is an agricultural waste and rich in silicon. The rice hull ash was extracted with sodium hydroxide solution to get a sodium silicate solution. The solution was neutralized with sulfuric acid solution to form silica hydrosol, which was immediately added appropriate quantity of tetraethyl orthosilicate (TEOS), and then gelated to be a gel. The aged gel was washed successively by water and ethanol, and finally dried at the atmosphere. The prepared material was characterized using transmission electron microscope (TEM) and Brunauer–Emmett–Teller (BET) measurements. The specific surface area of the prepared material is high as 500m2/g with a bulk density of 0.33g/cm3. The diameters of the pores inside the prepared materials are between 5 and 60nm.