Electrical Conductivity of Solutions of Ionic Liquids with Methanol, Ethanol, Acetonitrile, and Propylene Carbonate

A series of solutions composed of air- and water-stable hydrophobic ionic liquids (ILs) [Etpy][Tf₂N], [Bupy][Tf₂N], [Pepy][Tf₂N], [EtM₄py][Tf₂N], and [BuM₄py][Tf₂N] were prepared. The electrical conductivity of the solutions was investigated at T = 298.15 K, respectively. Then the electrical conductivity of solutions of [Bupy][Tf₂N] and [Hepy][Tf₂N] in acetonitrile/propylene carbonate were investigated at temperature range from (283.15 to 313.15) K. The correlation of concentration and electrical conductivity was fitted according to the empirical Casteel–Amis (CA) equation. The maximum electrical conductivity was extrapolated by the fitted result. The influence of the successive methylene (−CH₂−) group and the organic solvent to the electrical conductivity was discussed. The temperature dependence of the electrical conductivity of the solutions, ILs [Bupy][Tf₂N] and [Hepy][Tf₂N] in acetonitrile/propylene carbonate, was fitted by the empirical Vogel–Fulcher–Tamman (VFT) equation at a volume ratio of 50 %.