This proposal is being awarded under the Materials Chemistry Initiative. Detection of chemical species using solid state devices is an emerging field of both fundamental and applied interest. Chemical sensors based on several different physicochemical principles have been developed. One major challenge is to design these devices such that they respond selectively to only very few chemical species. The proposed research program comprises a collaborative effort between Sandia National Laboratories and the University of New Mexico. It is aimed at the development and exploration of a new generation of well-defined, inorganic membranes that will allow us to fine-tune interactions of molecules with surfaces. Applied to sensor surfaces, these structures with channel diameters in the one- nanometer range can be used to first selectively admit certain molecules into the membrane, and if so desired catalytically convert the adsorbed target molecules within the channel system. The experimental approach includes the hydrothermal formation of oriented molecular sieve channels on single crystal planes, exploration of zeolite-amorphous microcomposites, and the use of organic templates in the sol-gel formation of thin porous metal oxide films. This research is a novel application and combination of chemistry that has been explored in other systems. The collaboration allows them to employ a unique combination of analytical techniques for the characterization of these systems, including thermodesorption, EXAFS, x-ray diffraction, electron microscopy, small-angle scattering as well as various spectroscopies.
