Microscopic theory of intrinsic shear and bulk viscosities |
| |
| Authors: | Wokyung Sung John Karkheck G Stell |
| |
| Institution: | (1) Department of Physics, State University of New York at Stony Brook, 11794 Long Island, New York;(2) Present address: Department of Chemical Engineering, University of Minnesota, 55455 Minneapolis, Minnesota;(3) Department of Mechanical Engineering, State University of New York at Stony Brook, 11794 Long Island, New York;(4) Departments of Mechanical Engineering and Chemistry, State University of New York at Stony Brook, 11794 Long Island, New York |
| |
| Abstract: | A microscopic theory of intrinsic shear and bulk viscosities of solutions is given for a model of particles that interact with hard-sphere cores and weak longrange attraction. The approximation considered (the velocity chaos assumption of the Enskog theory) can be expected to yield quantitatively useful values for viscosities of the model solute-solvent system when the solute particles are not much larger than the solvent particles. Under solute-solvent mixing conditions of constant pressure and temperature we find that the intrinsic viscosities of a hard-sphere solute in a hard-sphere solvent can be positive or negative, depending upon size and mass ratios; for solute and solvent particles whose mass ratio equals their volume ratio, the intrinsic shear and bulk viscosities are always positive for solute particles larger than solvent particles: in the opposite case, the intrinsic shear viscosity is always negative while the intrinsic bulk viscosity is for the most part negative, becoming positive again when the solute particle is sufficiently small. For solute particles smaller than solvent particles, this result is sensitive to change in mass ratio. The addition of solvent-solvent attraction is found to lower the intrinsic viscosities substantially; the addition of solute-solvent attraction raises it. Detailed quantitative analysis of these effects is given. |
| |
| Keywords: | Kinetic theory transport coefficients intrinsic shear viscosity intrinsic bulk viscosity |
| 本文献已被 SpringerLink 等数据库收录！ |
|
