Thermodynamic, excess Properties and Intermolecular interactions of ionic liquid 1-Ethyl-3-Methylimidazolium thiocyanate and propylene carbonate mixtures

The densities, dynamic viscosities, and electrical conductivities of the ionic liquid (IL) 1-ethyl-3-methylimidazolium thiocyanate ([C(2)mim][SCN]) and its mixtures with propylene carbonate(PC) were measured as functions of temperature over the whole composition range at atmospheric pressure. The excess molar volumes (V-E) and dynamic viscosity deviations (Delta eta) of the mixtures were calculated and the change of V-E and Delta eta were fitted by the Redlich-Kister (R-K) polynomial equation. The temperature dependences of dynamic viscosity and electrical conductivity of the mixture were graphically described by the Vogel-Fulcher-Tammann (VFT) equation. The Casteel-Amis four-parameter (C-A) equation was used to described the electrical conductivities dependences of IL mole fraction. To describe the intermolecular interactions of the mixtures, the optimized structures and energetics of each component of the mixture are calculated by DFT method. The hydrogen bonding between 1-ethyl-3-methylimidazolium cation([C(2)mim](+)) and PC are enhanced, and the addition of PC can weaken the interaction between the [C(2)mim](+) and [SCN](-).