POLY 93 |
| Polymeric membranes currently used for commercial gas separations have thin dense skins of polymer, with thicknesses of the order of 100 nm, overlaying a porous support stucture. This presentation will focus on laboratory-made films of thicknesses approaching 100 nm and how these films differ in key properties, like permeation, from the bulk polymer. In particular, these thin films show very rapid physical aging which will be described using numerous examples. Elliposometry has proven to be a powerful tool for measuring thickness and tracking density via refractive index measurement. Changes in density and refractive index (or density) are intimately connected to the change in gas permeability observed during the aging process. |
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Mark Scholars Symposium
2:00 PM-4:15 PM, Sunday, 10 September 2006 San Francisco Marriott -- Nob Hill A, Oral
Division of Polymer Chemistry |