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Control of ordered structure and morphology of cubic mesoporous silica SBA-1 via direct synthesis of thiol-functionalization

Kao, Hsien-Ming and Shen, Tzu-Yi and Wu, Jyun-Da and Lee, Lung-Ping (2008) Control of ordered structure and morphology of cubic mesoporous silica SBA-1 via direct synthesis of thiol-functionalization. MICROPOROUS AND MESOPOROUS MATERIALS, 110 (2-3). pp. 461-471.

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Official URL: http://www.sciencedirect.com/science?_ob=ArticleUR...

Abstract

Well-ordered cubic mesoporous silicas SBA-1 functionalized with thiol groups have been synthesized via co-condensation of tetraethoxysilane (TEOS) and 3-mercaptopropyltrimethoxysilane (MPTMS) templated by cetyltriethylammonium bromide (CTEABr) under strongly acidic conditions. Various synthesis parameters such as HCl concentration, synthesis temperature, and time for hydrothermal treatment were systematically investigated as a function of MPTMS contents. The materials thus obtained were characterized by a variety of techniques including powder X-ray diffraction (XRD), solid-state C-13 and Si-29 NMR spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and nitrogen sorption measurements. Direct evidence of the presence of chemically attached thiol moieties was provided by solid-state Si-29 and C-13 NMR spectroscopy. A high degree of structural ordering was still retained when MPTMS loading was incorporated up to 20 mol% in the synthesis mixture. Increasing the synthesis temperature and the time for the hydrothermal treatment not only increased the degree of framework cross-linking, but also did not lead to the undesirable phase transformation as often observed in the conventional synthesis of pure silica SBA-1. SEM results reveal that the morphology of thiol-functionalized SBA-1 depends on the HCI concentration used in the synthesis. The sample prepared with a low acid concentration exhibits a highly isotropic morphology with more facets than that of pure silica SBA-1, whereas it changes to a spherical shape as the acid concentration is increased. The maximum content of the attached thiol group (-SH) in the mesoporous framework is 2.39 mmol/g. The thiol-functionalized SBA-1 mesoporous materials are efficient Hg2+ adsorbents. (C) 2007 Elsevier Inc. All rights reserved.

Item Type:Article
Uncontrolled Keywords:mesoporous organosilica; thiol functionalization; co-condensation
Subjects:Analytical Science > Microscopy and probe methods
Material Science > Functional and hybrid materials
ID Code:6098
Deposited By:IoN
Deposited On:04 Sep 2009 14:14
Last Modified:04 Sep 2009 14:14

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