Absorption- and Pressure-induced Structural Transition Exhibiting V-shaped Density Change in Imidazolium-based Ionic Liquid + CO2 System

摘要

The density of ionic liquid (M) + CO2 systems was measured by X-ray absorption method and excess molar volume was evaluated to investigate the volumetric behavior under a CO2 absorption process up to 20 MPa. A V-shaped density plot was observed, and three types of expanded/compressed trends were classified based on the excess molar volume of the IL. The volumetric behavior of the IL strongly depends on the CO2 amount absorbed in the IL's cavities.