THIOL-ANCHORED SILICA AND ITS OXIDIZED FORM - SOME DIVALENT-CATIONS CHEMISORBED IN AQUEOUS AND NONAQUEOUS SOLVENTS

The silylating agent 3-trimethoxysilyl-1-propanethiol was immobilized on silica gel in xylene and this modified silica surface was also oxidized in water with a permanganate solution. Both silicas were characterized by elemental analysis, infrared spectroscopy, thermogravimetry and carbon NMR in solid state. Sulphur analysis showed 0.98 mmol of thiol groups and one fourth of these as oxidized groups per gram of support. These groups chemisorb in batches according to the following divalent cations: nickel, cobalt, copper and mercury from both aqueous and non-aqueous solvents. Mercury is the most adsorbed cation for thiol (7.46 and 8.55 x 10(-4) mol g(-1)) and the oxidized (4.15 and 5.21 x 10(-4) mol g(-1)) silicas in ethanol and water solutions, respectively.