AC/DC conductivity and dielectric relaxation behavior of aqueous solutions of 1-butyl-3-methylimidazolium chloride

The complex relative dielectric function epsilon*(f) = epsilon' - j epsilon '' of aqueous solutions of 1-butyl-3-methylimidazolium chloride [BMiM][Cl] of varying concentrations, has been measured using precision LCR meter in the frequency range 20 Hz to 2 MHz at four different temperatures 293.15, 303.15, 313.15 and 323.15 K. Complex ac conductivity sigma*(f) of the liquid samples have been determined from the measured epsilon*(f). DC conductivity sigma(dc) of the samples have also been determined. Values of sigma(dc) at different concentrations have been fitted to the empirical Casteel-Amis (CA) equation. The influence of concentration and temperature variation on the complex permittivity and electrical conductivity of the solutions of [BMiM][Cl] in distilled water has been discussed. The molar conductivities and the infinite dilution conductance of these ionic liquids have also been determined. Orientational relaxation behavior of the aqueous solutions of [BMiM][Cl] has also been studied by measuring complex permittivity in the frequency range 1 GHz to 20 GHz using vector network analyzer. Various processes contributed to the electrical/dielectric properties of the solutions of [BMiM][Cl] in distilled water have been explored.