A Study on the Volumetric and Rheological Properties of Binary Mixtures of [bmim]PF6 Ionic Liquid and Aromatic Compounds

In this work, some thermophysical and transport properties of binary mixtures of ionic liquid 1- butyl -3- methyl imidazolium hexafluoro phosphate ([bmim] PF6) with some aromatic compounds, i.e. toluene and paraxylene, were measured and analyzed. The temperature and composition dependencies of the density and viscosity have been studied in these mixtures. Also, the dependence of viscosity on the shear rate were investigated. The small intercepts of plots of viscosity versus shear rate show that the studied mixtures are moderately non-Newtonian fluids. The viscosities of these mixtures are quadratic functions of temperature. This fact shows that the studied fluids have non-Arrhenius behavior. Temperature dependence of viscosity data was fitted using four known equations, namely, Power-law, Litovitz, VFT, and Ghatee et al. equations. Also, the activation thermodynamic parameters of these mixtures were calculated. The positive values of Gibbs free energy of activation show that the slip of two layers of the fluid is a non-spontaneous process. The composition dependence of these mixtures are fitted well with McAlister equation.