Date of Award

4-23-2008

Document Type

Thesis open access

Abstract

The controlled preparation of active sites on heterogeneous catalysts could improve several catalyst systems by optimizing catalyst efficiency and increasing reaction selectivity. Cetyltrimethylammonium bromide (CTAB) micelles were used as templating structures to encapsulate and deposit aminopropyltriethoxysilane (APS) onto silica. Methods of determining the number of available surface amines were explored; in particular, cobalt(II) titrations and ninhydrin tests were developed. Further characterization of the surface amines after micelle removal and surface alkylation with tetramethyldisilazane (TMDS) was performed by using fluorescence resonance energy transfer (FRET). Indole‐3‐propionic acid, a fluorescence donor, and a variety of fluorescence acceptor molecules have been reacted with the surface amines on APS micelle‐templated and APS grafted silica to provide a distribution of distances between the amines using the Förster radii of the specific donor and acceptor pairs. These FRET studies can be used to determine the extent of isolation of the active sites on oxide supports using the proposed templating scheme.

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Chemistry Commons

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