Effect of chemical grafting on the surface structure of porous bentonite as a support in gas chromatography

Abstract

The effect of thermal and chemical treatments on the variation of specific surface area of porous bentonite as a support was studied. The surface area of bare bentonite thermally treated at 950°C and then washed with 6N HC1 was measured to be 3.01 m^/g. Chemical grafting for the same treated bentonite by the condensation of PEG-20 M at 280° C formed a non-extractable monomolecular layer of PEG-20M. This grafting process changed the surface structure of bare bentonite and contributed to the good separation of hydrocarbon mixture C5-C12 with a very good precision and sensitivity.