Investigation of salt effect of some inorganic salts and ionic liquids for ibuprofen in aqueous solutions of 1-propanol: volumetric, acoustic and viscometric studies

In this study, salt effect of sodium chloride, potassium chloride, choline acetate (ChAce), choline lactate (ChLac) and choline propionate (ChPro) for ibuprofen in aqueous solutions of 1-propanol were investigated using volumetric, acoustic and viscometric methods. Density, speed of sound and viscosity of quaternary systems (ibuprofen + water + 1-propanol + NaCl/KCl/ChAce/ChLac/ChPro) were measured at temperatures T = 288.15, 298.15 and 308.15 K. Limiting apparent molar volume and limiting apparent molar isentropic compressibility at infinite dilution were calculated using experimental density and speed of sound. Limiting apparent molar volume of ibuprofen increased in the presence of NaCl and KCl; whereas limiting apparent molar volume decreased in the presence of ionic liquids. Therefor NaCl and KCl have salting-out effect; whereas ChAce, ChLac and ChPro have salting-in effect. Also, molar free energy activation of solvent and solute were evaluated using viscosity data. The molar free energy activation of solute was greater than solvent; therefore ibuprofen has a maker structure nature in solvents (water + 1-propanol + NaCl/KCl/ChAce/ChLac/ChPro).