Title

Spatial distribution of organic functional groups supported on mesoporous silica nanoparticles (2): a study by 1H triple-quantum fast-MAS solid-state NMR

Publication Date

8-10-2018

Department

Ames Laboratory; Chemistry

Campus Units

Ames Laboratory, Chemistry

OSTI ID+

1467595

Report Number

IS-J 9736

DOI

10.1039/C8CP04425B

Journal Title

Physical Chemistry Chemical Physics

Volume Number

20

Issue Number

34

First Page

22203

Last Page

22209

Abstract

The distribution of organic functional groups attached to the surface of mesoporous silica nanoparticles (MSNs) via co-condensation was scrutinized using 1D and 2D 1H solid-state NMR, including the triple-quantum/single-quantum (TQ/SQ) homonuclear correlation technique. The excellent sensitivity of 1H NMR and high resolution provided by fast magic angle spinning (MAS) allowed us to study surfaces with very low concentrations of aminopropyl functional groups. The sequential process, in which the injection of tetraethyl orthosilicate (TEOS) into the aqueous mother liquor was followed by dropwise addition of the organosilane precursor, resulted in deployment of organic groups on the surface, which were highly clustered even in a sample with a very low loading of ∼0.1 mmol g−1. The underlying mechanism responsible for clustering could involve fast aggregation of the aminopropyltrimethoxysilane (APTMS) precursor within the liquid phase, and/or co-condensation of the silica-bound molecules. Understanding the deposition process and the resulting topology of surface functionalities with atomic-scale resolution, can help to develop novel approaches to the synthesis of complex inorganic–organic hybrid materials.

DOE Contract Number(s)

AC02-07CH11358

Language

en

Department of Energy Subject Categories

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE

Publisher

Iowa State University Digital Repository, Ames IA (United States)

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