Theory of transport in dilute solutions, suspensions, and pure fluids. I. Translational diffusion
Journal Article
·
· J. Chem. Phys.; (United States)
We develop a microscopic theory of transport for dilute suspensions and solutions in which the dynamics of the solute--solvent (i.e., tagged particle--fluid particle) collision is treated on a level of the Enskog approximation, appropriately modified by the presence of the solvent sea, which is described hydrodynamically. The treatment of the solvent as a continuum using appropriate generalized boundary conditions gives rise to an effective solute--solvent core radius as well as an effective solute--solvent reduced mass. In this paper, we consider translational diffusion of the solute particle of arbitrary size and mass. We derive an analytically simple expression for the coefficient of diffusion, which yields the correct hydrodynamic limit (Stokes--Einstein law). Our expression for self-diffusion D/sup S/ (diffusion of a tagged particle in a fluid of identical particles) is in excellent agreement with molecular-dynamical results, showing both an increase over the Enskog value D/sup S//sub E/ at low fluid density as well as a quite precipitous drop at liquid densities (the enhanced caging effect). Our result turns out to be in close agreement with the Stokes--Einstein law for a wide range of solute particle sizes provided the solvent is at liquid density.
- Research Organization:
- Department of Chemistry, State University of New York, Stony Brook, New York 11794
- OSTI ID:
- 5121303
- Journal Information:
- J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 80:7; ISSN JCPSA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Theory of transport in dilute solutions, suspensions, and pure fluids. II. Intrinsic shear and bulk viscosities
Effective density and viscosity of a suspension
On the Brownian motion of a massive sphere suspended in a hard-sphere fluid. II. Molecular dynamics estimates of the friction coefficient
Journal Article
·
Sat Mar 31 23:00:00 EST 1984
· J. Chem. Phys.; (United States)
·
OSTI ID:5121289
Effective density and viscosity of a suspension
Journal Article
·
Tue Feb 28 23:00:00 EST 1995
· Journal of Rheology; (United States)
·
OSTI ID:6579092
On the Brownian motion of a massive sphere suspended in a hard-sphere fluid. II. Molecular dynamics estimates of the friction coefficient
Journal Article
·
Fri Jul 01 00:00:00 EDT 1994
· Journal of Statistical Physics
·
OSTI ID:471848