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Title

Dielectric and structural properties of aqueous nonpolar solute mixtures

Author(s)

Shvab, I.;  Sadus, Richard J.

Abstract

The dielectric properties and molecular structure of water mixtures with different nonpolar solutes (methane and noble gases) are studied using molecular dynamics. The water-water, water-solute, and solute-solute interactions are calculated using the combination of a polarizable potential [J. Li, Z. Zhou, and R. J. Sadus, J. Chem. Phys. 127, 154509 (2007)] for water plus the Lennard-Jones potential. The effect of solute size and concentration on the solubility of the system, hydrogen bonding, dielectric constant, and dipole moment are investigated over a temperature range of 278-750 K and solute percentage mole fractions up to 30%. Solute particles affect the structure of water, resulting in the compression of oxygen-oxygen and oxygen-hydrogen radial distribution functions. The influence of the solute extends both to relatively low concentrations and high temperatures. The coordination numbers of aqueous solutions of the nonpolar solutes appear to be proportional to the size of the solute particles. Our study shows the destructive influence of the nonpolar solute on both the tetrahedral water structure and hydrogen bond formation at solute concentrations greater than 30%. The presence of nonpolar particles typically decreases both the dielectric constant and dipole moment. The decrease of dielectric constant and water dipole moment is directly proportional to the solute concentration and temperature.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Molecular Simulation

Source

Journal of Chemical Physics, Vol. 137, no. 12 (Sep 2012), article no. 124501

Publication year

2012

FOR Code(s)

02 Physical Sciences;  03 Chemical Sciences;  09 Engineering

Keyword(s)

Aqueous solutions;  Dielectric properties;  Molecular properties;  Nonpolar solutes;  Water mixtures

Publisher

American Institute of Physics

ISSN

0021-9606

Publisher URL

http://dx.doi.org/10.1063/1.4753940

Copyright

Copyright © 2012 American Institute of Physics. The published version is reproduced with the kind permission of the publisher.

Full text

Peer reviewed