Journal of Colloid and Interface Science, Vol.310, No.2, 362-368, 2007
Adsorption of toxic organic compounds from water with hydrophobic silica aerogels
Silica monolith aerogels with different degrees of hydrophobicity were prepared by incorporating methyltrimethoxysi lane (MTMS) or trimethylethoxysi lane (TMES) in standard sol-gel synthesis followed by supercritical drying of gels with carbon dioxide (CO2) at 40 degrees C and 100 bar. The hydrophobicity of the aerogels was tested by measuring the contact angle (theta). The acrogels were also characterised by FTIR, DSC, and porosity measurements. Adsorption capacity measurements show that such modified hydrophobic silica aerogels are excellent adsorbents for different toxic organic compounds from water. In comparison to granulated active carbon (GAC) they exhibit capacities which are from 15 to 400 times higher for all tested compounds. Adsorption properties of hydrophobic silica aerogel remain stable even after 20 adsorption/desorption cycles. (C) 2007 Elsevier Inc. All rights reserved.
Keywords:hydrophobic silica aerogels;sol-gel synthesis;supercritical carbon dioxide drying;adsorption;volatile organic compounds