Molecular Dynamics Simulations of the Phase Behavior of [BMIM]Cl-Water Mixtures

Currently, processing of biomass requires the use of densely-charged electrolytic media, such as strong acids or ionic liquids, to enable the dissolution of cellulose into its constituent sugars. However, the dissolution of the cellulose will lead to the release of trapped water molecules inside the cellulose matrix, possibly leading to instability of the solvent medium, particularly if the medium is an ionic liquid. Using molecular dynamics simulations, we examine the thermodynamic behavior of densely charged mixtures (including high-ionic-strength aqueous solutions of salts, acids and ionic liquids), with respect to the mole fraction of water. Specifically, we report results obtained from simulations of ionic liquid [bmim][cl] in the presence of water. All simulations are carried out based on OPLS force fields, and are performed at conditions corresponding to those commonly under biomass processing conditions. We report results on the structure, dynamics, and phase aggregation tendencies of these mixtures on the molecular scale.