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Title: Molecular simulation of thermodynamic and transport properties for the H{sub 2}O+NaCl system

Abstract

Molecular dynamics and Monte Carlo simulations have been carried out to obtain thermodynamic and transport properties of the binary mixture H{sub 2}O+NaCl at temperatures from T = 298 to 473 K. In particular, vapor pressures, liquid densities, viscosities, and vapor-liquid interfacial tensions have been obtained as functions of pressure and salt concentration. Several previously proposed fixed-point-charge models that include either Lennard-Jones (LJ) 12-6 or exponential-6 (Exp6) functional forms to describe non-Coulombic interactions were studied. In particular, for water we used the SPC and SPC/E (LJ) models in their rigid forms, a semiflexible version of the SPC/E (LJ) model, and the Errington-Panagiotopoulos Exp6 model; for NaCl, we used the Smith-Dang and Joung-Cheatham (LJ) parameterizations as well as the Tosi-Fumi (Exp6) model. While none of the model combinations are able to reproduce simultaneously all target properties, vapor pressures are well represented using the SPC plus Joung-Cheathem model combination, and all LJ models do well for the liquid density, with the semiflexible SPC/E plus Joung-Cheatham combination being the most accurate. For viscosities, the combination of rigid SPC/E plus Smith-Dang is the best alternative. For interfacial tensions, the combination of the semiflexible SPC/E plus Smith-Dang or Joung-Cheatham gives the best results. Inclusion of watermore » flexibility improves the mixture densities and interfacial tensions, at the cost of larger deviations for the vapor pressures and viscosities. The Exp6 water plus Tosi-Fumi salt model combination was found to perform poorly for most of the properties of interest, in particular being unable to describe the experimental trend for the vapor pressure as a function of salt concentration.« less

Authors:
; ; ;  [1]
  1. Chemical Engineering Program, Texas A and M University at Qatar, P.O. Box 23874, Doha (Qatar)
Publication Date:
OSTI Identifier:
22413346
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 141; Journal Issue: 23; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-9606
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; BINARY MIXTURES; COMPUTERIZED SIMULATION; DENSITY; FLEXIBILITY; INCLUSIONS; INTERACTIONS; LIQUIDS; MOLECULAR DYNAMICS METHOD; MONTE CARLO METHOD; PRESSURE DEPENDENCE; SODIUM CHLORIDES; SURFACE TENSION; VAPOR PRESSURE; VISCOSITY; WATER

Citation Formats

Orozco, Gustavo A., Jiang, Hao, Panagiotopoulos, Athanassios Z., E-mail: azp@princeton.edu, Moultos, Othonas A., and Economou, Ioannis G.. Molecular simulation of thermodynamic and transport properties for the H{sub 2}O+NaCl system. United States: N. p., 2014. Web. doi:10.1063/1.4903928.
Orozco, Gustavo A., Jiang, Hao, Panagiotopoulos, Athanassios Z., E-mail: azp@princeton.edu, Moultos, Othonas A., & Economou, Ioannis G.. Molecular simulation of thermodynamic and transport properties for the H{sub 2}O+NaCl system. United States. https://doi.org/10.1063/1.4903928
Orozco, Gustavo A., Jiang, Hao, Panagiotopoulos, Athanassios Z., E-mail: azp@princeton.edu, Moultos, Othonas A., and Economou, Ioannis G.. Sun . "Molecular simulation of thermodynamic and transport properties for the H{sub 2}O+NaCl system". United States. https://doi.org/10.1063/1.4903928.
@article{osti_22413346,
title = {Molecular simulation of thermodynamic and transport properties for the H{sub 2}O+NaCl system},
author = {Orozco, Gustavo A. and Jiang, Hao and Panagiotopoulos, Athanassios Z., E-mail: azp@princeton.edu and Moultos, Othonas A. and Economou, Ioannis G.},
abstractNote = {Molecular dynamics and Monte Carlo simulations have been carried out to obtain thermodynamic and transport properties of the binary mixture H{sub 2}O+NaCl at temperatures from T = 298 to 473 K. In particular, vapor pressures, liquid densities, viscosities, and vapor-liquid interfacial tensions have been obtained as functions of pressure and salt concentration. Several previously proposed fixed-point-charge models that include either Lennard-Jones (LJ) 12-6 or exponential-6 (Exp6) functional forms to describe non-Coulombic interactions were studied. In particular, for water we used the SPC and SPC/E (LJ) models in their rigid forms, a semiflexible version of the SPC/E (LJ) model, and the Errington-Panagiotopoulos Exp6 model; for NaCl, we used the Smith-Dang and Joung-Cheatham (LJ) parameterizations as well as the Tosi-Fumi (Exp6) model. While none of the model combinations are able to reproduce simultaneously all target properties, vapor pressures are well represented using the SPC plus Joung-Cheathem model combination, and all LJ models do well for the liquid density, with the semiflexible SPC/E plus Joung-Cheatham combination being the most accurate. For viscosities, the combination of rigid SPC/E plus Smith-Dang is the best alternative. For interfacial tensions, the combination of the semiflexible SPC/E plus Smith-Dang or Joung-Cheatham gives the best results. Inclusion of water flexibility improves the mixture densities and interfacial tensions, at the cost of larger deviations for the vapor pressures and viscosities. The Exp6 water plus Tosi-Fumi salt model combination was found to perform poorly for most of the properties of interest, in particular being unable to describe the experimental trend for the vapor pressure as a function of salt concentration.},
doi = {10.1063/1.4903928},
url = {https://www.osti.gov/biblio/22413346}, journal = {Journal of Chemical Physics},
issn = {0021-9606},
number = 23,
volume = 141,
place = {United States},
year = {2014},
month = {12}
}