Computer Simulation of Molecular Interactions in Supercritical Solvents.
Abstract
The structure and dynamics of supercritical mixtures were studied by molecular dynamics and integral equation calculations. Integral equation calculations were performed on the systems naphthalene in carbon dioxide (non-volatile solute; attractive mixture); and neon in xenon (volatile solute; repulsive mixture), at high dilution and at supercritical temperatures. The attractive system exhibited significant short-ranged solvent enrichment around the solute at sub-critical densities. Molecular dynamics calculations were performed for the system benzene in carbon dioxide, from 50% to twice the critical density, at supercritical temperatures. Enhancements in local density of carbon dioxide around benzene were more pronounced at sub-critical density. Neither local density augmentation nor proximity to the critical point affected the solute's translational and rotational diffusivities. These quantities varied smoothly with bulk density across the range of conditions investigated. The main conclusion from this work is that local-bulk asymmetries are most pronounced at sub-critical densities, and that the dynamics of solute molecules at high dilution are unaffected by the proximity to the solvent's critical point.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 10, 1996
- Accession Number
- ADA309963
Entities
People
- P. G. Debenedetti
Organizations
- Princeton University