Viscosity of liquid mixtures: The Vesovic-Wakeham method for chain molecules
Abstract
New expressions for the viscosity of liquid mixtures, consisting of chain-like molecules, are derived by means of Enskog-type analysis. The molecules of the fluid are modelled as chains of equally sized, tangentially joined, and rigid spheres. It is assumed that the collision dynamics in such a fluid can be approximated by instantaneous collisions. We determine the molecular size parameters from the viscosity of each pure species and show how the different effective parameters can be evaluated by extending the Vesovic-Wakeham (VW) method. We propose and implement a number of thermodynamically consistent mixing rules, taking advantage of SAFT-type analysis, in order to develop the VW method for chain molecules. The predictions of the VW-chain model have been compared in the first instance with experimental viscosity data for octane-dodecane and methane-decane mixtures, thus, illustrating that the resulting VW-chain model is capable of accurately representing the viscosity of real liquid mixtures.
- Publication:
-
Journal of Chemical Physics
- Pub Date:
- February 2012
- DOI:
- 10.1063/1.3685605
- Bibcode:
- 2012JChPh.136g4514D
- Keywords:
-
- liquid mixtures;
- organic compounds;
- thermodynamics;
- viscosity;
- 66.20.Cy;
- 64.75.Cd;
- 64.75.Ef;
- 65.20.Jk;
- 66.20.Ej;
- Theory and modeling of viscosity and rheological properties including computer simulation;
- Phase equilibria of fluid mixtures including gases hydrates etc.;
- Mixing;
- Studies of thermodynamic properties of specific liquids;
- Studies of viscosity and rheological properties of specific liquids