Physicochemical properties of binary mixtures of 1,1,3,3-tetramethylguanidine imidazolide ionic liquid with water and alcohols

In this work, densities and viscosities of aqueous solution of 1,1,3,3-tetramethylguanidine imidazolide ([TMG]IM) ionic liquid were measured at temperatures from T   =   (293.15 to 313.15)   K. Volumetric properties including excess molar volumes V E , apparent molar volumes, partial molar volumes, and excess partial molar volumes were calculated from the experimental density. Viscosity deviations Δ η , Gibbs energy and excess Gibbs energy of activation for viscous flow were deduced from the viscosity. Moreover, electrical conductivities κ and refractive indices of binary mixtures of [TMG]IM with water and alcohols were determined at 298.15   K. The results show that V E values of {[TMG]IM (1)   +   water (2)} mixture are negative over the whole composition range, while Δ η and refractive index deviations Δ n D values exhibit positive deviations, indicating that the hydrogen bonding interaction between [TMG]IM and water is dominant. The absolute values of V E and Δ η of the mixture decrease with the increasing temperature. The V E , Δ η , and Δ n D can be fitted by the Redlich–Kister equation with satisfactory results. The concentration-dependent κ of the studied systems are fitted to Casteel–Amis equation, showing that the κ values of {[TMG]IM (1)   +   water (2)} mixture are much higher than those of {[TMG]IM (1)   +   ethanol (2)} mixture.