Preparation and adsorptive properties of silica gels

Abstract

Silica gels prepared by different methods have been found to give varied types of sorption isothermals, indicating a wide variation in pore size and distribution. The factors determining this variation have been investigated and in an attempt to alter the shape of the isothermals, several different gels were treated with various water-repellents and fatty acids. The sorption of water on these treated gels was found to be specific. Finally, the hysteresis loops of several gel systems have been scanned and the results have been explained on the basis of the open-pore theory. Defects have bean pointed out in both the ink-bottle theory as represented by Katz, and Cohan's version of the open-pore theory.