Thermodynamic perturbation theory for mixtures of spherical and tetrahedral molecules
1988; Taylor & Francis; Volume: 64; Issue: 4 Linguagem: Inglês
10.1080/00268978800100423
ISSN1362-3028
AutoresMichael Bohn, Rolf Lustig, Johann Fischer, Frank Köhler,
Tópico(s)Thermodynamic properties of mixtures
ResumoA Weeks-Chandler-Andersen type perturbation theory (PT) is presented for the Helmholtz energy of liquid mixtures consisting of spherical and tetrahedral molecules. Use is made of a hard fused sphere anisotropic reference system. The excess properties g E, h E and v E are predicted for the mixtures CS2/CCl4 and Ar, Kr, Xe, CH4/CF4. CCl4 and CF4 are modelled as tetrahedrons, the other substances are treated as spheres. The consequences of molecular shape on the prediction of excess values is discussed. The tetrahedrons are modelled with and without an additional interaction site at the centre of mass. The influence on the excess properties turned out to be small. For the system Xe/CF4 the shape influence on the concentration dependence of the excess properties is small, and is compared with experiment. For the CF4 mixtures it is shown that unlike interaction parameters determined in the liquid phase predict the excess virial coefficients almost within the experimental accuracy.
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