Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

The effect of interactions between organic solvents and water on the interfacial and bulk properties of N-ethyl-N-methylmorpholinium dicyanamide, [EMMor][DCA] were discussed on the base of the limiting activity coefficients 13z values. The experimental 13z values were determined by gas -liquid chromatography at temperatures from (298.15 to 368.15) K for 61 assorted solutes damong them, alkanes (linear, branched, or cyclic), alkenes, alkynes, aromatic hydrocarbons, alcohols, water, thiophene, tetrahydrofuran, 1,4-dioxane, ethers, acetone, ketones, acetonitrile, pyridine, and 1-nitropropane. The partial molar excess Gibbs free energy dG1E,z, the partial molar excess enthalpy dH1E,z, and entropy at reference temperature TrefdS1E,z at infinite dilution were calculated from the experimental 13z values obtained over this temperature range. The gas -liquid partition coefficient KL was calculated for each solute and discussed in light of the Abraham solvation parameter model. The density and viscosity of the [EMMor][DCA] as a function of temperature were also measured. The selectivity and capacity for six separation problems were calculated from 13z and compared to literature values for selected ionic liquids. These separation problems are central to the petroleum and organic chemistry industry. The data presented here shows that [EMMor][DCA] reveals large selectivity equal 140, 273, 538, 73.1, 87.5 and 10.2 in heptane/benzene, heptane/thiophene, heptane/ethanol, hexane/ethyl acetate, ethyl-tert-butyl ether, ETBE/ethanol and THF/water separation problems at T = 328.15 K. The capacities were 0.22, 0.42, 0.83, 0.17 and 2.97 for benzene, thiophene, ethanol, ethyl acetate, and water at the same temperature.