Effect of the Attraction Range of Pair Potential on the Thermodynamic Properties of Fluids


Department of Chemistry,Sharif University of Technology


Recently, a new potential model has been proposed for the intermolecular interactions of model pure fluids and it was shown that the derived Equation Of State (EOS), based on this potential, can properly predict the thermodynamic properties of these fluids. In addition to simplicity and, to some extent, the realistic form, this potential has a parameter (\alpha) which controls the range of the attraction tail. In the first part of this study, the proposed potential and derived EOS are extended to binary mixtures of model fluids. In a similar manner to that of the pure fluids, the results obtained are consistent with the data available from simulation studies. In the second part, after modification of the model potential through finding a general temperature dependency for \alpha, the modified potential is used to calculate some equilibrium thermodynamic properties of real pure fluids and their binary mixtures. Again, it was found that the modified potential can suitably predict the thermodynamic properties for pure, as well as binary, mixtures of real fluids.