Synthesis and characterization of silica gels functionalized with monochlorotriazinyl beta-cyclodextrin and their sorption capacities towards organiccompounds

Different supports, containing a new derivative of beta-cyclodextrin - mono chlorotriazinyl beta-cyclodextrin (beta-CDMCT) - used for the reduction of pollutants in waste water, have been prepared. They are based on silica gel , initially either coated with polyethyleneimine (PEI) or grafted with 3-am inopropyltrimethoxysilane, functionalized in a second step with beta-CDMCT. In order to obtain sorbents with high beta-cyclodextrin content and maximu m accessibility of the beta-CD cavity, the funtionalization was studied whi le varying experimental conditions. Thermogravimetry, Raman spectroscopy, s pecific surface area and pore size distribution were used for the character ization of supports. Sorption experiments show that these sorbents have sor ption capacities towards some organic pollutants. The mechanism of sorption is both physical adsorption in the polymer network (for supports obtained by coating) and/or the formation of an inclusion complex between beta-CDMCT and guest molecules.