Transport and optical properties of 1-octyl 3-methylimidazolium bromide ionic liquid in water + Ethanol/1-propanol mixtures at T = (298.2, 308.2 and 318.2) K

Abstract

In this work, viscosities (η), conductivities (Ʌ) and refractive index (nD) for the ternary systems of 1-octyl-3-methylimidazolium bromide [OMIm]Br ionic liquid in the Ethanol/1-propanol+water mixtures were measured in different mass fractions of alcohol in water (w/w% = wAlcohol/wmixture = 0, 10, 20 and 30%) at T = (298.2, 308.2 and 318.2) K. The viscosity data was analyzed using jones-dole equation to derive the viscosity B-coefficient which indicates the solute-solvent interactions. The temperature dependence of the viscosity was described by fluidity equation. Ion association constants (Ka) and limiting molar conductivities (Ʌ0) of [OMIm]Br were obtained by using Fuoss–Onsager equation based on conductivity measurements. In addition, refractive index (nD) of [OMIm]Br were measured for the binary and ternary water+[OMIm]Br + Ethanol/1-propanol mixtures. The obtained results were compared to the predicted values using the Heller equation. Excess refractive index (nDE) for binary and ternary mixtures and regression parameters of the Redlich–Kister and Cibulka equation were obtained at different temperatures.