Advanced mesoporous organosilica material containing microporous β-cyclodextrins for the removal of humic acid from water

A new mesoporous organosilica material (β-CD-Silica-4%) containing microporous β-cyclodextrins (β-CDs) has been prepared by the co-polymerization of a silylated β-CD monomer with tetraethoxysilane in the presence of a structure-directing template, cetyltrimethylammonium bromide. Solid-state 13C and 29Si NMR studies provided evidence for the presence of covalently attached β-CDs in the mesoporous material. Nitrogen adsorption experiments showed that β-CD-Silica-4% material had a BET surface area of 460 m2/g and an average mesopore diameter of 2.52 nm. Small-angle powder X-ray diffraction pattern of β-CD-Silica-4% material revealed the lack of highly ordered mesoporous structure. Adsorption experiments showed that β-CD-Silica-4% material removed up to 99% of humic acid from an aqueous solution containing 50 ppm of humic acid at a solution-to-solid ratio of 100 ml/g.