Molecular dynamics study of the mechanism of cellulose dissolution in the ionic liquid 1-n-butyl-3-methylimidazolium chloride

N,N'-Dialkylimidazolium ionic liquids (ILs) show promise as non-derivatizing 'green' solvents for the dissolution and processing of cellulose. To better understand how these ILs solvate this and other polysaccharides at the molecular level, we have performed molecular dynamics (MD) simulations of neat 1-n-butyl-3-methylimidazolium chloride ([C ₄mim]Cl) at 298, 313, 333, 343, 353, 363, and 373 K, as well as 5 and 10 wt% cellobiose solutions in [C ₄mim]Cl at 363 K. Static, dynamic, and thermodynamic quantities have been derived from the collected data. Our findings agree well with experimental data from various sources. In particular, analysis of structural features and hydrogen bonding patterns between [C4mim]Cl and cellobiose are consistent with results from NMR relaxation studies which indicate that the IL Cl ^- ions interact with the carbohydrate OH groups in a ∼ 1:1 ratio.