Excess Thermodynamic Properties for Binary Mixtures of Ionic Liquid 1-Ethyl-3-methylimidazolium Ethyl Sulfate and 2-Methoxyethanol from T = (298.15 to 328.15) K at Atmospheric Pressure

Abstract

The density (rho), speed of sound (u) and refractive index (n (D)) for pure [Emim][EtSO4], 2-methoxyethanol and their binary mixtures were measured using an Anton Paar vibrating tube density and sound velocity meter (DSA 5000 M) and automatic refractometer over the whole composition range as a function of temperature between 298.15 and 328.15 K in steps of 10 K at atmospheric pressure. Experimental values were used to calculate the excess values of molar volumes (), partial molar volumes (), partial molar volumes at infinite dilution (), isentropic compressibility (), acoustic impedance (Z (E)), free length (), speeds of sound (), internal pressure (), free volume () and deviations in refractive index ( ) for the binary mixtures. These properties were fitted to a Redlich-Kister type equation to obtain the binary coefficients and the standard deviations. The negative values of , , ,, and and positive values for Z (E), ,, and indicate the existence of strong interactions between the components. This was further supported by IR spectroscopy analysis.