Thermophysical Characterization of the Mixtures of the Ionic Liquid 1-Ethyl-3-Methylimidazolium Acetate with 1-Propanol or 2-Propanol

A thermal and physical characterization of the binary mixtures of the ionic liquid 1-ethyl-3-methylimidazolium acetate ([C(2)mim][OAc]) with 1-propanol or with 2-propanol was carried out. Thermogravimetric analyses confirmed that the stability of the ionic liquid is not reduced by the presence of the propanols. The density, viscosity, refractive index, and surface tension of the two binary systems were experimentally determined over the entire composition range, at atmospheric pressure, and from 288.15 to 348.15 K (for the system [C(2)mim][OAc] + 1-propanol) or to 338.15 K (for the system [C(2)mim][OAc] + 2-propanol). All properties were found to decrease with an increase in temperature and in the concentration of alcohol in the system. Negative excess molar volume, positive logarithm viscosity change of mixing, and mostly negative surface tension change of mixing were obtained from the experimental data for the isotherms investigated. An analysis of the trends of these property changes of mixing in systems [C2mim][0Ac] + alcohol was carried out. In assessing the trend for the surface tension change of mixing, experimental data for the surface tension of the system [C2mim] [OAc] + methanol were also obtained.