Effect of composition and temperature variations on thermophysical properties of binary and ternary mixtures of 1-ethyl-3-methylimidazolium ethylsulfate with 1-butanol and/or methanol

Abstract

The thermophysical properties, densities, ρ, speeds of sound, u and dynamic viscosities, η of pure ionic liquid, 1-ethyl-3-methylimidazolium ethylsulfate, ([EMIM][ES]), and solvents 1-butanol, methanol and of their binary and ternary mixtures have been measured experimentally at a temperature range from (298.15–323.15) K, with an interval of 5 K and at pressure 0.1 MPa by using Anton Paar vibrating tube density and sound velocity meter DSA 5000M and Lovis microviscometer 2000M. The excess molar volumes, VE, isentropic compressibilities, κs, molar isentropic compressibilities, Кs,m, excess molar isentropic compressibility, Кs,mE, and viscosity deviations Δη have been calculated using the experimental ρ, u and η data at the same temperature range and pressure for [EMIM][ES] + 1-butanol/methanol binary systems and the VE, κs, excess isentropic compressibility, κsE and Δη for ternary [EMIM][ES] + 1-butanol + methanol system. The VE, κsE, Кs,mE and Δη data for the studied binary/ternary systems have been fitted to Redlich-Kister equation. The variations in VE,κsE, Кs,mE and Δη values with changes in composition and temperature have been discussed in terms of hydrogen bonding, ion–dipole interactions and structural effects on mixing of ILs and solvents.