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Title: Molecular Dynamics Modeling of Ion Adsorption to the Basal Surfaces of Kaolinite

Journal Article · · J. Phys. Chem. C
DOI:https://doi.org/10.1021/jp065687+· OSTI ID:1007646

Molecular dynamics simulation is used to study the mechanisms involved in the adsorption of various ions to the basal surfaces of kaolinite. Analysis of simulation data indicates that cations and anions adsorb preferably on the siloxane and gibbsite surfaces of kaolinite, respectively. Strong inner-sphere adsorption of chlorine at aluminum vacancies on the gibbsite surface and the occurrence of chlorine-driven inner-sphere adsorption of cesium and sodium on the gibbsite surface for high ionic strengths are observed. Cesium ions form strong inner-sphere complexes at ditrigonal cavities on the siloxane surface. Outer-sphere cesium is highly mobile and only weak adsorption may occur. A small amount of sodium adsorbs on the siloxane surface as inner-sphere complexes at less clearly defined sites. Like cesium, sodium only forms very weak outer-sphere complexes on this surface. Inner-sphere complexes of cadmium and lead do not occur on either surface. Relatively strong outer-sphere cadmium and lead complexes are present on the siloxane surface at ditrigonal cavities.

Research Organization:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Organization:
USDOE
OSTI ID:
1007646
Journal Information:
J. Phys. Chem. C, Vol. 111, Issue (18) ; 2007; ISSN 1932-7447
Country of Publication:
United States
Language:
ENGLISH