Glen E. Fryxell

Supercritical Processing of Functionalized Size Selective Microporous Materials

Abstract A supercritical fluid silanation process is applied to effectively functionalize commercial microporous materials without blocking the pore channels. In this approach, supercritical carbon dioxide (SCCO 2 ) is used to deposit mercaptopropyl silane into the microporosity of zeolite beta. The thiol group was subsequently oxidized into sulfonic acid. The size selective catalytic properties of the SCCO 2 modified zeolite compare well with similar materials prepared by an in situ silanation process reported by Jones et al. The active functional groups were delivered to the internal pore surface of the microporous material and remain accessible to molecules that can enter the pore channels. The supercritical process provides an alternative approach to functionalize microporous materials because of the enhanced diffusivity of the functional molecules in the micropore channels and accelerated reaction kinetics. Furthermore, the supercritical process simplifies the materials preparation and may open up new opportunities for commercial zeolites.

Hybrid Mesoporous Materials with Functionalized Monolayers

Mesoporous materials have great potential for environmental and industrial processes, but many applications require the materials to exhibit specific surface chemistry and binding sites. A new approach has been developed so that organized functional monolayers are covalently bound to mesoporous supports. The functionalized hybrid materials show exceptional selectivity and capacity for removing heavy metals from waste streams. Tailored hybrid materials have also shown potential to selectively bind anions and radionuclides. Rational design of the surface properties of mesoporous materials will lead to more sophisticated functional composites.

Interfacial Chemistry in Self-Assembled Nanoscale Materials with Structural Ordering

This paper discusses the interfacial chemistry encountered in the self-assembly of ordered nanoscale materials based on surfactant liquid crystalline structures. The paper contains three sections. The first section gives a brief introduction to the interfacial chemistry in the co-assembly of surfactants and inorganic materials. The second section discusses the formation of inorganic–inorganic nanocomposites, the properties of such materials, and the interfacial atomic structures. The last section discusses hybrid nanoscale materials with functional monolayers, their interfacial chemistry, and their potential applications.