Extraction of Sodium Chloride from Water and Solubility of Water in Hydrophobic Trialkylammonium Alkanoate-Based Ionic Liquids

The sodium chloride extraction from aqueous solutions by using hydrophobic trialkylammonium alkanoate ionic liquids (ILs) is studied experimentally. The water solubility in these ILs is also determined. It is found that trialkylammonium alkanoate ILs show sodium chloride extraction efficiencies up to 0.101 g NaCl extracted/g NaCl start. This efficiency cannot be explained by the low water uptake (up to 0.02 g(water)/g(IL)) in the IL. Instead, the sodium chloride extraction must be attributed to other factors, such as steric hindrance considerations. Steric hindrance considerations also explain the dependence of sodium chloride extraction efficiency on the IL structure. Kinetic experiments were performed to ensure a state of chemical equilibrium.