Shear viscosity of model mixtures by nonequilibrium molecular dynamics. II. Effect of dipolar interactions

Abstract

In a recent paper [Lee and Cummings, J. Chem. Phys. 99, 3919 (1993)], we presented nonequilibrium molecular dynamics calculations of the shear viscosity of pure liquid argon, pure liquid krypton, and argon/krypton liquid mixtures at constant temperature (T=135 K) and pressure (P=40 bar) as the base case for a consistent study of the role of intermolecular potentials on the transport properties of molecular liquids and their mixtures. In this paper, nonequilibrium molecular dynamics is used to study the shear viscosity of pure dipolar fluids, polar/nonpolar fluid mixtures, and polar/polar fluid mixtures at the same temperature and pressure. The fluids are assumed to interact via Lennard-Jones intermolecular potentials augmented by point dipole/point dipole potentials in the case of polar/polar interactions. By comparing the computed shear viscosity with that for corresponding nonpolar pure fluids and mixtures, the effect of dipolar interactions on the shear viscosity can be clearly delineated.