GEOC 144 |
| R. James Kirkpatrick1, Andrey G. Kalinichev1, Jianwei Wang1, and Randall T. Cygan2. (1) Department of Geology, University of Illinois at Urbana-Champaign, 1301 W Green St, 245 NHB, Urbana, IL 61801, (2) Geochemistry Department, Sandia National Laboratories, Albuquerque, NM 87185-0750 |
| The nanoscale structural and dynamical behavior of water at mineral interfaces strongly affects the surface reactivity of these phases, their ability to adsorb and intercalate solution species, their swelling behavior, and, eventually, their macroscopic-scale role in many geochemical and environmental processes. Molecular dynamics computer simulation using the recently developed CLAYFF semi-empirical force field is a powerful tool to quantitatively probe the fundamental atomistic scale structural environments and dynamical behavior of H2O molecules and ions on and near mineral surfaces. This presentation will discuss computational results for (001) surfaces of a number of representative minerals: brucite, gibbsite, portlandite, talc, kaolinite (two surfaces), and muscovite. Depending on the surface structure and composition, H2O molecules can in various proportions donate hydrogen bonds to the surface and ohter water molecules and/or accept H-bonds from the surface or structural OH groups, thus developing an H-bonding network across the interface that has variable strength and stability. |
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Interfacial Phenomena: Linking Atomistic and Macroscopic Properties
8:05 AM-11:30 AM, Wednesday, March 31, 2004 Marriott -- Marquis NW, Oral
Division of Geochemistry |