Na{sup +}--Cl{sup {minus}} ion pair association in supercritical water

Journal Article · Fri Dec 01 04:00:00 EST 1995 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.470707· OSTI ID:135441

Chialvo, A A; Cummings, P T ^[1]; Cochran, H D ^[2]; Simonson, J M; Mesmer, R E ^[3]

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1. Department of Chemical Engineering, University of Tennessee, Knoxville, Tennessee 37996-2200 (United States)
2. Chemical Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6268 (United States)
3. Chemical and Analytical Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110 (United States)

Molecular dynamics simulations of supercritical electrolyte solutions with three different ion--water models are performed to study the anion--cation potential of mean force of an infinitely dilute aqueous NaCl solution in the vicinity of the solvent`s critical point. The association constant for the ion pair Na{sup +}/Cl{sup {minus}} and the constant of equilibrium between the solvent-separated and the contact ion pairs are determined for three models at the solvent critical density and 5% above its critical temperature. The realism of the aqueous electrolyte models is assessed by comparing the association constants obtained by simulation with those based on high temperature conductance measurements. Some remarks are given concerning the calculation of the mean-force potential from simulation and the impact of the assumptions involved. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

• Research Organization: Oak Ridge National Laboratory
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 135441
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 21 Vol. 103; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
AGGLOMERATION
AQUEOUS SOLUTIONS
CHLORINE IONS
ELECTROLYTES
ION PAIRS
SODIUM IONS
SUPERCRITICAL STATE