title: Sol-Gel Synthesis of Ordered β-Cyclodextrin-Containing Silicas.
abstract: New approaches for β-cyclodextrin-containing silicas synthesis were demonstrated. Materials with hexagonally ordered mesoporous structure were prepared by postsynthesis grafting and by co-condensation methods. β-Cyclodextrin activated by a N,N'-carbonyldiimidazole was employed for postsynthesis treatment of 3-aminopropyl-modified MCM-41 support as well as for sol-gel synthesis with β-cyclodextrin-containing organosilane and tetraethyl orthosilicate participation in the presence of cetyltrimethylammonium bromide. The successful incorporation of cyclic oligosaccharide moieties in silica surface layer was verified by means of FT-IR spectroscopy and chemical analysis. Obtained β-cyclodextrin-containing materials were characterized by X-ray diffraction, transmission electron microscopy, and low-temperature adsorption-desorption of nitrogen. In spite of commensurable loading of β-cyclodextrin groups attained by both proposed approaches (up to 0.028 μmol · m(-2)), it was found that co-condensation procedure provides uniform distribution of β-cyclodextrin functionalities in silica framework, whereas postsynthesis grafting results in modification of external surface of silica surface. Adsorption of benzene from aqueous solutions onto the surface of β-cyclodextrin-containing materials prepared by co-condensation method was studied as the function of time and equilibrium concentration. Langmuir and Freundlich models were used to evaluate adsorption processes and parameters. Adsorption experiments showed that β-cyclodextrin-containing silicas could be promising for the trace amount removal of aromatics from water.
authors.affiliation: Chuiko Institute of Surface Chemistry, NAS of Ukraine, 17 General Naumov Str, Kyiv, 03164, Ukraine. trofymchuk_iryna@ukr.net.
authors.forename: Iryna Mykolaivna
authors.initials: IM
authors.lastname: Trofymchuk
authors.affiliation: Chuiko Institute of Surface Chemistry, NAS of Ukraine, 17 General Naumov Str, Kyiv, 03164, Ukraine.
authors.forename: Nadiia
authors.initials: N
authors.lastname: Roik
authors.affiliation: Chuiko Institute of Surface Chemistry, NAS of Ukraine, 17 General Naumov Str, Kyiv, 03164, Ukraine.
authors.forename: Lyudmila
authors.initials: L
authors.lastname: Belyakova
keywords: Activating agent; MCM-41; Organosilane; Postsynthesis grafting; Sol-gel synthesis; β-Cyclodextrin