二氧化硅气凝胶对挥发性有机污染物的吸附性能研究

以TEOS为前驱体，乙醇为溶剂，氢氟酸为催化剂，一步法合成了常规二氧化硅气凝胶。经乙醇超临界干燥后，通过SEM，FTIR和N2吸脱附分析仪等仪器对二氧化硅气凝胶样品进行表征，以更好地了解吸附机理与性质的关系。结果表明，样品的比表面积高达519 m2/g，孔体积为1.9 cm3/g，平均孔径为15.15 nm，是一种优良的吸附材料。制备的样品用作测试甲苯、对二甲苯和苯三种挥发性有机化合物的吸附效果。结果表明，二氧化硅气凝胶对三种污染物都具有很高的吸附量，其高吸附能力归因于气凝胶的三维纳米网络结构。样品对甲苯，对二甲苯和苯的最大吸附能力分别为1422.8 mg/g，707.4 mg/g和1299.4 mg/g。综上所述，二氧化硅气凝胶是一种很有前景的处理挥发性有机化合物的吸附剂，具有优异的吸附性能。

Study on the Adsorption Performance of Silica Aerogel on Volatile Organic Compounds

The regular silica aerogel was synthesized by using TEOS as precursor, ethanol as solvent and hydrofluoric acid as catalyst, one-step process. After alcohol supercritical method the silica aerogel sample was characterized by SEM, FTIR, and nitrogen adsorption-desorption isotherms to better understand the relationship of the adsorption mechanism-property. The results indicated that the sample has a high specific surface area of 519 m2/g, pore volume of 1.9 cm3/g and a large pore size of 15.15 nm. The prepared sample was tested for using as an adsorbent for volatile organic compounds (VOCs) disposal. Methylbenzene, paraxylene and benzene were selected as typical adsorbates due to their extensive utilization in industry. Silica aerogel has achieved high adsorption amounts for all of them. The high adsorption ability of silica aerogel is attributedSto the nanonetwork structure, the little pore diameter. The maximum adsorption capabilities are up to 1422.8 mg/g, 707.4 mg/g, and 1299.4 mg/g for methylbenzene, paraxylene and benzene, respectively. Therefore, the silica aerogel is a promising potential adsorbent for VOCs disposal with the superior adsorption ability.