NMR study of adsorption techniques for organic compounds on silica surfaces

Abstract

The adsorption of benzenoid aromatic compounds on porous silica has been studied by 13C and 19F NMR and by BET measurements. Small chemical shifts between the resonances of methyl groups or fluorine substituents in the microcrystalline bulk material and the adsorbed species can be used to monitor the degree of adsorption. The results for various adsorption techniques, in particular dry adsorption by grinding mixtures of organic material and silica or by ball mill treatment of such mixtures are compared. Annealing and ball mill treatment was found to be most effective. Copyright © 1999 John Wiley & Sons, Ltd.