Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

This paper reports experimental data of density and refractive index for the binary systems of 1-butyl-3-methylimidazolium tetrafluoroborate, [Bmim][BF4], with 1,4-dioxane, and 1-ethyl-3-methylimidazolium tetrafluoroborate, [Emim][BF4], with 1,4-dioxane and ethylene glycol (EG). Moreover, for the system [Bmim][BF4] + EG we report here refractive index data. The measurements for the systems with EG were made over the entire composition range at atmospheric pressure (101 +- 2 kPa) and in the temperature range from (293.15 to 353.15) K for densities and from (298.15 to 323.15) K for refractive indices. Because at room temperature the mixtures of both ionic liquids with 1,4-dioxane have indicated partial immiscibility, liquid liquid phase equilibrium was determined. The excess molar volumes, VE, and deviations in refractive index, ?n, were calculated by using the measured experimental data and correlated by the Redlich Kister type equations. VE values are positive for the system with EG and negative for both systems with 1,4-dioxane, ?n presenting an opposite sign. To probe the interactions in mixtures and to correlate the excess molar volumes of the mixtures the Prigogine Flory Patterson (PFP) theory has been used. Moreover, to correlate VE and predict density and refractive index of the mixtures the Lorentz Lorenz equation was applied.