FUEL 182 |
| The emphasis on the development of novel architectures for integrating photochemical molecular assemblies into practical devices for conversion of solar to chemical energy has rapidly increased due to the demands of energy consumption. Motivated by these demands, the current research is aimed at designing appropriate zeolite membranes that can be used for photochemical applications. The framework of the Linde Type L zeolite (LTL) provides ideal geometrical properties for the arrangement and stabilization of incorporated supramolecular systems due its one dimensional pore structure. Zeolite L seed layers were prepared by the dip-coating of various sizes and morphologies of well-dispersed LTL crystallites on porous alpha alumina substrates and grown by an optimized hydrothermal secondary growth process at ~110oC. Aqueous dispersions of LTL crystallites with different loading concentrations were prepared using polymers at alkaline pH to relieve surface tension, as well as ultrasonication to assist with homogenization. To avoid the formation of large intracrystalline pores during hydrothermal secondary growth of zeolite membranes, the effect of polymer type and molecular weight on the seeded layer morphology was investigated by electron microscopy. Moreover, the ideal secondary growth solution, temperature and time were investigated for the synthesis of impurity and defect free membranes. The supported zeolite membranes were characterized for integrity, density, defect morphology and population by scanning electron microscopy, ellipsometry, and statistical methods that employ membrane transport properties such as stationary or non-stationary single gas permeance and permporometry techniques. |
|
Inorganic Membranes for Energy and Environmental Applications
1:00 PM-6:00 PM, Tuesday, August 21, 2007 Boston Park Plaza -- Chartes River Room, Oral
Division of Fuel Chemistry |