Title: Accessibility of amino groups in postsynthetically modified mesoporous silica
Authors : Ritter, Hanna
Brühwiler, Dominik
Published in : The Journal of Physical Chemistry Part C
Volume(Issue) : 113
Issue : 24
Pages : 10667
Pages to: 10674
Publisher / Ed. Institution : American Chemical Society
Issue Date: 2009
License (according to publishing contract) : Licence according to publishing contract
Type of review: Peer review (Publication)
Language : English
Subjects : 2009; ICBC; Mesopores; Accessibility
Subject (DDC) : 540: Chemistry
Abstract: The accessibility of amino groups in postsynthetically functionalized mesoporous silica MCM-41, MCM-48, and SBA-15 is investigated by reaction with fluorescein isothiocyanate (FITC). The quantitative analysis of the surface-grafted amino groups in relation to the amount of coupled FITC over a wide range of loadings affords information about potential pore blocking. In the pore diameter domain of 3−4 nm, the actual pore size of materials with a one-dimensional channel system (MCM-41) strongly affects the FITC coupling yield and the distribution of the anchored fluorescein moieties. In the case of SBA-15 (7.6 nm pore diameter), the accessibility of the grafted amino groups is similar to what is expected for a material with a completely open surface. However, grafting in the intrawall micropores of SBA-15 leads to a substantial fraction of inaccessible amino groups. As a direct consequence of short channel lengths and large external surface area, excellent accessibility is also observed for nanometer-sized MCM-41 (3.2 nm pore diameter).
Departement: Life Sciences und Facility Management
Organisational Unit: Institute of Chemistry and Biotechnology (ICBT)
Publication type: Article in scientific Journal
DOI : 10.1021/jp901983j
ISSN: 1932-7447
URI: https://digitalcollection.zhaw.ch/handle/11475/2650
Appears in Collections:Publikationen Life Sciences und Facility Management

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