Prediction of Refractive Indices of Binary Mixtures of Ionic Liquids and Water

Figure 3

Experimental refractive index values (circular symbols) as a function of ionic liquid (IL) mole fraction (x_IL) for the four selected IL + H₂O systems belong to imidazolium (M5), pyrrolidinium (M2), pyridinium (M14), and ammonium (M22) families along with the predicted values using Gladstone–Dale (green line) and Newton (red line) approach at 298.15 K. The poorest results (highest average percentage deviations) were obtained for these systems in respective families.