GEOC 101 |
| Jianwei Wang, Andrey G. Kalinichev, and R. James Kirkpatrick. Department of Geology, University of Illinois at Urbana-Champaign, 1301 W. Green St., Urbana, IL 61801 |
| The muscovite KAl2(Si3Al)O10(OH)2 (001) surface is commonly used in studies of fluid-mineral interaction, but many aspects of its behavior remain controversial. Molecular dynamics simulations of water adsorbed on this surface using the CLAYFF force field provides important new insight into the near-surface fluid structure and dynamics. The molecules of the first layer are adsorbed at the centers of 6-member Si,Al tetrahedral rings at which K is absent, donating two H-bonds (HBs) to the basal oxygens. Those in the second layer are adsorbed primarily above the basal oxygens, donating one HB to them and on to the water molecules of the first adsorbed layer. Those in the third layer are also adsorbed above the basal oxygens, but hydrate surface K laterally. Those in the forth layer hydrate K and water molecules in the layers closer to the surface. The computed hydration energy is consistent with the experimental enthalpy of adsorbed thin water films on muscovite surfaces. |
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Poster Session
6:00 PM-9:00 PM, Tuesday, March 30, 2004 Anaheim Convention Center -- Hall A, Poster
Division of Geochemistry |