Apparent Molar Volumes and Electrical Conductance of Ionic Liquids [C_nmim]Br (n = 8, 10, 12) in Ethylene Glycol, N,N-Dimethylformamide, and Dimethylsulfoxide at 298.15 K

摘要

Solution densities and conductivities for solutions of [C_nmim]Br (n = 8, 10, 12) ionic liquids (ILs) in ethylene glycol, N,N-dimethylformamide, and dimethylsulfoxide have been determined at 298.15 K as a function of ionic liquid concentration. The apparent molar volumes, standard partial molar volumes, molar conductivities, and the limiting molar conductivities of the ILs have been derived from the experimental data. On the basis of the values of the standard partial molar volume and the limiting molar conductivity of the Br~ anion available in the literature, the standard partial molar volumes and the limiting molar conductivities for the cations have also been reported in the three organic solvents. These data help to examine the effect of alkyl chain length of the cations and properties of the solvents. It was shown that the standard partial molar volumes of the ILs and their cations increased, but the limiting molar conductivities decreased linearly with the increase of the alkyl chain length. The fluidity of the solvents played an important role in the conductivity properties.