Vapor Pressure Measurements for Binary Mixtures Containing Ionic Liquid and Predictions by the Conductor-like Screening Model for Real Solvents

Abstract

The vapor pressures for binary systems containing the ionic liquid (IL) 1-ethyl-3-methylimidazoliun tetrafluoroborate ([EMIM][BF4]) and a solute were measured with a modified equilibrium still, and the solutes investigated were benzene, toluene, thiophene, and water. The results indicate that the IL [EMIM][BF4] produces an obvious effect on the vapor pressures of binary systems, and the vapor pressures increase with the temperature. The vapor pressures of binary mixtures (i.e., [EMIM][BF4] + benzene, [EMIM][BF4] + thiophene, and [EMIM][BF4] + toluene) first increase with the increase of mole fraction of the solute, and then almost keep stable. However, the vapor pressures of the mixture of water and [EMIM][BF4] increase linearly with the increase of mole fraction of water. The vapor pressure experimental data for the binary systems were compared with the predicted values by the conductor-like screening model for real solvents (COSMO-RS) model. The results demonstrate that the COSMO-RS model gives quantita...