Excess properties of non-ideal binary mixtures containing water, methanol and ethanol by molecular simulation

Excess properties provide information about the nature of molecular interactions in binary mixtures. Since experimental measurements of these properties may be difficult and time consuming, their prediction is important. Monte Carlo simulations are used here to calculate the excess properties of binary mixtures. Excess volume and excess enthalpy are investigated by molecular modeling and simulation for aqueous, methanolic and ethanolic binary liquid mixtures with the following components: benzene, chloroform, dimethyl ether, ethylene oxide, toluene, tribromomethane and 2-bromo-2-chloro-1,1,1-trifluoroethane. These mixtures are of considerable interest because of their S-shaped composition dependence of excess thermodynamic quantities. The comparison with experimental data from the literature for excess volume and excess enthalpy shows that one binary interaction parameter per mixture typically needs to be adjusted for a quantitative agreement.