(98f) A Study of Liquid-Liquid Equilibrium for 1-N-Hexyl-3-Methylimidazolium Bis(Trifluoromethylsulfonyl)Imide, Toluene and Water System

The main objective of this project is to study the phase equilibrium of ionic liquids (IL) with other compounds, in order to evaluate ILs as extraction solvents for liquid-liquid separations. ILs are organic salts with immeasurably low vapor pressures. This characteristic means they do not evaporate, and cannot contribute to air pollution. A preliminary phase diagram of a ternary system composed of an ionic liquid, namely 1-n-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (hmim Tf2N), toluene (C7H8) and water (H2O), was constructed to study liquid-liquid equilibrium properties of this system. The number of phases present for various feed conditions was determined visually. The approximate concentration of water in each phase, once at equilibrium, was measured using a Karl Fisher Coulometer. Approximate toluene concentrations were measured with a UV-Visible spectrophotometer in the range of 200-300 nm. The experimental data collected during this summer research allowed the construction of a preliminary phase diagram, which is presented here. Further research is necessary to complete the phase diagram.