Study on the thermodynamic properties of ether-functionalized imidazolium-based ionic liquids.

Abstract: Ether-functionalized imidazolium-based ionic liquids (EFIILs) exhibit extremely high SO2 solubility. In this paper, a series of EFIILs were prepared, and their structures were confirmed by 1H NMR. The thermodynamic properties of EFIILs, such as density, viscosity and surface tension, were measured from (298.15 to 343.15) K at atmospheric pressure. The molecular volume, coefficient of thermal expansion, standard entropy, surface entropy, and surface enthalpy were calculated from the experimental data. The results indicate that density, viscosity and surface tension of the specific EFIILs show linear decline as temperature rises, and decrease with the increase of ether chain length of the cation at the same temperature. The surface properties of EFIILs were also discussed systematically. [Copyright &y& Elsevier]