A combinatorial activity coefficient model for symmetric and asymmetric mixtures

see the original item page
in the repository's web site and access all digital files if the item*

1995 (EN)
A combinatorial activity coefficient model for symmetric and asymmetric mixtures (EN)

Kalospiros, NS (EN)
Tassios, DP (EN)
Voutsas, EC (EN)

N/A (EN)

A new combinatorial activity coefficient model, based on the Staverman-Guggenheim (SG) one, is developed in this study. It involves a system-dependent exponent, determined from the size ratio of its components only, and is useful for group-contribution models. The model, referred to as R-UNIFAC, is applied to the prediction of activity coefficients in the following nearly athermal mixtures: (a) alkane / alkane mixtures; (b) alkane / polymer mixtures; (c) polymer / solvent mixtures, where the activity coefficient data were obtained by constant-pressure Monte Carlo simulations. For all these mixtures the residual contribution to the activity coefficient is expected to be close to zero. The new model yields satisfactory predictions for all systems considered, independently of system asymmetry, comparable to those obtained with free-volume models such as the Entropic-FV and p-FV ones. It has the advantage, however, that it does not require pure-component liquid molar volumes and, thus, is directly applicable to systems containing compounds where such volumes are not accurately known or supercritical fluids. © 1995. (EN)


Paraffins (EN)
Solvents (EN)
Mixtures (EN)
Molar volume (EN)
Mixtures of alkanes (EN)
Free volume (EN)
Free-volume (EN)
Forecasting (EN)
Activity coefficients (EN)
Monte Carlo methods (EN)
Supercritical fluids (EN)
Combinatorial expression (EN)
Monte Carlo simulations (EN)
Polymer solutions (EN)
Combinatorial activity coefficient (EN)
Mathematical models (EN)
Polymers (EN)

Εθνικό Μετσόβιο Πολυτεχνείο (EL)
National Technical University of Athens (EN)

Fluid Phase Equilibria (EN)




*Institutions are responsible for keeping their URLs functional (digital file, item page in repository site)