Templating Mesoporous Silica with Chiral Block Copolymers and Its Application for Enantioselective Separation
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- 作者：A. Gabashvili ; Dana D. Medina ; A. Gedanken ; Y. Mastai
- 刊名：Journal of Physical Chemistry B
- 出版年：2007
- 出版时间：September 27, 2007
- 年：2007
- 卷：111
- 期：38
- 页码：11105 - 11110
- 全文大小：260K
- 年卷期：v.111,no.38(September 27, 2007)
- ISSN：1520-5207
文摘
In this paper we describe the synthesis of chiral mesoporous silica based on chiral block copolymers ofpoly(ethylene oxide) and of D-phenylalanine (PEO-b-D-Phe) as a surfactant template. The resulting porousstructures are characterized by nitrogen sorption experiments, transmission electron microscopy, and small-angle XRD. It is shown that chiral block copolymers of PEO-b-D-Phe are effective as a surfactant templatefor the preparation of silica materials with highly ordered periodic mesoporous structures of hexagonal symmetrywith a pore size of ca. 5 nm and high surface areas of ca. 700 m2/g. The enantioselectivity feature of thisporous silica, after the extraction of the chiral copolymers, was examined by selective adsorption of enantiomersand racemic solutions of valine. The selective adsorption was measured by circular dichroism (CD)spectroscopy. A chiral selectivity factor of 2.34 was found with the D enantiomer of valine adsorbed preferably.