Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

Measurements of the solution densities for 1-alkyl (n = 2, 4, 6)-3-methylimidazolium bromide ionic liquids (ILs) in acetonitrile + water mixed-solvent media containing acetonitrile mass fractions () of 0.1, 0.2, and 0.4 were undertaken at temperatures of (293.15, 303.15, and 313.15) K. The IL concentration was also varied in the measurements. The apparent molar volumes (VF) and standard partial molar volumes (VFdeg ) were computed from the experimental data. The effects of the IL cation alkyl chain length, the temperature, and the relative permittivity of the medium on the standard partial molar volumes were also determined. It was observed that VFdeg has a linear relationship with respect to the number of carbon atoms in the alkyl chain of the IL cation. The VFdeg values were found to decrease systematically with increasing temperature and mass fraction of acetonitrile in the mixed-solvent medium. The results are discussed in terms of the solvodynamic and thermodynamic interactions that prevail in the IL solutions investigated.