Electrical conductivity and dipolar relaxation of binary dimethylimidazolium chloride-water solutions: A molecular dynamics study

The non-thermal response of neat dimethylimidazolium chloride salts and their binary mixtures with water have been investigated by means of non-equilibrium molecular dynamics simulation at an electric field intensity of 10− 3 V/Å, in terms of electrical conductivity and dipolar relaxation (as metrics of translational and rotational response, respectively). Using Green-Kubo and transient time correlation function (TTCF) analysis, the electrical conductivity of each system has been estimated. It was found that the systems' conductivity at 450 K increased, while dipolar relaxation times for both water molecules and dimethylimidazolium ions decreased, with decreasing ionic liquid mole fraction. This indicates greater scope for accelerated response to external electric fields in less associated ionic liquids.