Multi-scale modelling of uranyl chloride solutions

Journal Article · Wed Jan 14 04:00:00 EST 2015 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4905008· OSTI ID:22415842

Nguyen, Thanh-Nghi; Duvail, Magali; Villard, Arnaud; Dufrêche, Jean-François ^[1]; Molina, John Jairo ^[2]; Guilbaud, Philippe ^[3]

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1. Institut de Chimie Séparative de Marcoule (ICSM), UMR 5257, CEA-CNRS-Université Montpellier 2-ENSCM, Site de Marcoule, Bâtiment 426, BP 17171, F-30207 Bagnols-sur-Cèze Cedex (France)
2. Fukui Institute for Fundamental Chemistry, Kyoto University, Takano-Nishihiraki-cho 34-4, Sakyo-ku, Kyoto 606-8103 (Japan)
3. CEA/DEN/DRCP/SMCS/LILA, Marcoule, F-30207 Bagnols-sur-Cèze Cedex (France)

Classical molecular dynamics simulations with explicit polarization have been successfully used to determine the structural and thermodynamic properties of binary aqueous solutions of uranyl chloride (UO{sub 2}Cl{sub 2}). Concentrated aqueous solutions of uranyl chloride have been studied to determine the hydration properties and the ion-ion interactions. The bond distances and the coordination number of the hydrated uranyl are in good agreement with available experimental data. Two stable positions of chloride in the second hydration shell of uranyl have been identified. The UO{sub 2}{sup 2+}-Cl{sup −} association constants have also been calculated using a multi-scale approach. First, the ion-ion potential averaged over the solvent configurations at infinite dilution (McMillan-Mayer potential) was calculated to establish the dissociation/association processes of UO{sub 2}{sup 2+}-Cl{sup −} ion pairs in aqueous solution. Then, the association constant was calculated from this potential. The value we obtained for the association constant is in good agreement with the experimental result (K{sub UO{sub 2Cl{sup +}}} = 1.48 l mol{sup −1}), but the resulting activity coefficient appears to be too low at molar concentration.

• OSTI ID: 22415842
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 2 Vol. 142; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
AQUEOUS SOLUTIONS
BOND LENGTHS
CONCENTRATION RATIO
COORDINATION NUMBER
DILUTION
DISSOCIATION
HYDRATION
ION PAIRS
MATHEMATICAL SOLUTIONS
MOLECULAR DYNAMICS METHOD
POLARIZATION
POTENTIALS
REACTION KINETICS
SOLVENTS
THERMODYNAMIC ACTIVITY
THERMODYNAMIC PROPERTIES
URANIUM DIOXIDE
URANYL CHLORIDES