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Advances in Materials Science and Engineering
Volume 2014, Article ID 850420, 8 pages
Research Article

Preparation of Silica Aerogel and Its Adsorption Performance to Organic Molecule

State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, Zhejiang University of Technology, Hangzhou 310032, China

Received 11 September 2013; Accepted 6 January 2014; Published 20 February 2014

Academic Editor: Kuo Chuan Ho

Copyright © 2014 Hong-xin Shi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Hydrophobic and lipophilic silica aerogel was prepared from water-glass by gelling, aging, silylation, and drying under atmospheric pressure and characterized by FT-IR and SEM. The effect of preparation process on aerogel density and the aerogel density on contact angle of water on it were investigated in detail. pH 6 is most beneficial to shorten gelling time and to obtain the lowest density of silica aerogel. Increasing TEOS concentration of aging solution to 25 v% could decrease aerogel density to 0.093 g/cm3. The silica aerogel exhibits good hydrophobicity even though its density is 0.30 g/cm3. There are few changes in their adsorption capacities after 3 cycles of adsorption-desorption. The adsorption performance of the silica aerogel to organic solvent in water is different from in pure solvents. The critical surface tension ( ) of the silica aerogel prepared here is about 30.8 mN/m. If the surface tension of aqueous solvent solution ( ) is greater than , it will wet the aerogel surface partially. If   ≤   , the solution will wet all aerogel surface and be adsorbed well. This work delivers us a method to adsorb solvents from their waste water by adjusting the surface tension of the waste water to lower than of the adsorbent.