THE INFLUENCE OF GRAFTED FUNCTIONAL-GROUPS ON THE ADSORPTION PROPERTIES OF SILICA

The adsorption properties of silica gel with grafted aminopropyl and g uanidinoethanethiol (GET) groups were studied by the techniques of ads orption under static conditions and gas chromatography. It was shown t hat molecules capable of forming hydrogen bonds are adsorbed on all mo dified samples more weakly than on the initial silica gel. The graftin g of GET radicals on the surface results in a noticiable increase in t he dispersion interaction with adsorbed molecules. Calculation of the contributions of molecular groups to the constant of adsorption equili brium showed that the thermodynamic characteristics of adsorption on a minosilochromes and aminosilicas with a polymeric layer of the modifyi ng agent have similar values. Such adsorbents can be used for investig ation of polar compounds, including organic bases.