Computer simulations of solvation dynamics in lithium clay materials
- Lawrence Berkeley National Lab., CA (United States)
Monte Carlo and molecular dynamics computer simulations were performed concurrently for the first time on lithium-smectites (montmorillonite, beidellite, and hectorite) at very low water content (about 0.5 monolayer). These simulation conditions were selected to provide a comparison with existing NMR, IR, neutron scattering, and X-ray diffraction data which have been interpreted in terms of inner-sphere (IS) Li surface complexes solvated by three water molecules exhibiting hindered rotational degrees of freedom. Our simulations predicted layer spacings (c-axis direction) ranging from 10.32 {angstrom} (Hectorite) to 11.93 {angstrom} (beidellite). Both IS and outer-sphere (OS) Li surface complexes formed in the interlayers of montmorillonite, whereas only one type of surface complex formed in the interlayers of beidellite (IS) and hectorite (OS). Lithium ions were solvated by 2, 3, or 4 water molecules. Some evidence of Li-hydrate rotation was seen for beidellite, but the other smectites showed no Li-hydrate rotational motion. However water molecules were observed to rotate about their C{sub 2} axes of symmetry in montmorillonite. Additional spectroscopic data are needed to resolve the differences between the simulation predictions and current experimental interpretations.
- OSTI ID:
- 560036
- Report Number(s):
- CONF-970443-; TRN: 97:005895-0110
- Resource Relation:
- Conference: 213. national meeting of the American Chemical Society, San Francisco, CA (United States), 13-17 Apr 1997; Other Information: PBD: 1997; Related Information: Is Part Of 213th ACS national meeting; PB: 2904 p.
- Country of Publication:
- United States
- Language:
- English
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