Investigation of the transition to liquid-liquid immiscibilitym for Lennard-Jones (12,6) systems, using Gibbs-ensemble molecular simulations

M. E. van Leeuwen, C. J. Peters, J. de Swaan Arons, Athanassios Z. Panagiotopoulos

Research output: Contribution to journalArticlepeer-review

31 Scopus citations

Abstract

Van Leeuwen M.E., Peters C.J., de Swaan Arons J. and Panagiotopoulos A.Z., 1991. Investigation of the transition to liquid-liquid immiscibility for Lennard-Jones (12,6) systems using Gibbs-ensemble molecular simulations. Fluid Phase Equilibria, 66: 57-75. The transition of liquid-liquid immiscibility in Lennard-Jones systems was studied using Gibbs-ensemble computer simulation. In order to obtain liquid-liquid immiscibility, a binary interaction parameter δ12 within the Lorentz-Berthelot combining rules was used to describe a deviation of the unlike-pair energy interaction parameter ε{lunate}*12 from the geometric mean. When δ12 is unity, the investigated system approximates to the mixture Ar-Kr at 143.15 K. The binary interaction parameter δ12 was varied over a range of 0.9-0.7, such that the phase behaviour of five hypothetical mixtures was simulated at one temperature. As δ12 decreased, the phase envelope was observed to widen (compared to the phase behaviour of a system with δ12 = 1) through a shift of the location of the liquid branch. A gradual deviation of the gas branch at higher pressures resulted in a positive azeotrope for δ12 = 0.75 and a hetero-azeotrope for δ12 = 0.7. For δ12 ≤ 0.75, liquid-liquid immiscibility was observed. Constant-(total) volume runs turned out to be more stable than constant-pressure runs in situations with large density fluctuations, such as for two coexisting liquids.

Original languageEnglish (US)
Pages (from-to)57-75
Number of pages19
JournalFluid Phase Equilibria
Volume66
Issue number1-2
DOIs
StatePublished - Jan 1 1991

All Science Journal Classification (ASJC) codes

  • Chemical Engineering(all)
  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Investigation of the transition to liquid-liquid immiscibilitym for Lennard-Jones (12,6) systems, using Gibbs-ensemble molecular simulations'. Together they form a unique fingerprint.

Cite this