The total and partial solubility parameters (dispersion, polar and hydrogen-bonding solubility parameters) of ten ionic liquids were determined. Intrinsic viscosity approaches were used that encompassed a one-dimensional method (1D-Method), and two different three-dimensional methods (3D-Method1 and 3D-Method2). The effect of solvent type, the dimethylacetamide (DMA) fraction in the ionic liquid, and dissolution temperature on solubility parameters were also investigated. For all types of effect, both the 1D-Method and 3D-Method2 present the same trend in the total solubility parameter. The partial solubility parameters are influenced by the cation and anion of the ionic liquid. Considering the effect on partial solubility parameters of the solvent type in the ionic liquid, it was observed that in both 3D methods, the dispersion and polar parameters of a 1-ethyl-3-methylimidazolium acetate/solvent (60:40 vol %) mixture tend to increase as the total solubility parameter of the solvent increases.

The Hildebrand solubility parameters of amidium ionic liquids were investigated using the approach of intrinsic viscosity. It was discovered that the nature of the anion influences the Hildebrand solubility parameters by which distillable trifluoromethanesulfonate-(TfO-) based ionic liquids present higher Hildebrand solubility parameters than bis-(trifluoromethylsulfonyl)imide-(NTf 2 -) based ionic liquids. In this work, we also studied the effect of dissolution temperature on the Hildebrand solubility parameters of ionic liquids. An increase in temperature from 25 to 60 °C results in a decrease in the Hildebrand solubility parameters of ionic liquids. Moreover, the cohesive energy density, molar internal energy, and enthalpy of dissolution were evaluated. The molar internal energy and enthalpy of dissolution are almost constant or show a slight decrease with increasing dissolution temperature for O-methylated TfO-based ionic liquids.