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

• DOI: 10.1016/j.chroma.2004.02.076
• Publication Date: 2004-04-10T06:51:45Z
• Authors: Chunqing Liu; Nathaniel Naismith; James Economy
• Keywords: Magnetic Resonance Spectroscopy; X-Ray Diffraction; beta-Cyclodextrins; Water; Adsorption; Silicon Dioxide; 01 natural sciences; Humic Substances; 0104 chemical sciences

A new mesoporous organosilica material (beta-CD-Silica-4%) containing microporous beta-cyclodextrins (beta-CDs) has been prepared by the co-polymerization of a silylated beta-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 beta-CDs in the mesoporous material. Nitrogen adsorption experiments showed that beta-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 beta-CD-Silica-4% material revealed the lack of highly ordered mesoporous structure. Adsorption experiments showed that beta-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.