title: Diffusion of 1-ethyl-3-methyl-imidazolium acetate in glucose, cellobiose, and cellulose solutions.
abstract: Solutions of glucose, cellobiose and microcrystalline cellulose in the ionic liquid 1-ethyl-3-methyl-imidazolium ([C2mim][OAc]) have been examined using pulsed-field gradient (1)H NMR. Diffusion coefficients of the cation and anion across the temperature range 20-70 °C have been determined for a range of concentrations (0-15% w/w) of each carbohydrate in [C2mim][OAc]. These systems behave as an "ideal mixture" of free ions and ions that are associated with the carbohydrate molecules. The molar ratio of carbohydrate OH groups to ionic liquid molecules, α, is the key parameter in determining the diffusion coefficients of the ions. Master curves for the diffusion coefficients of cation, anion and their activation energies are generated upon which all our data collapses when plotted against α. Diffusion coefficients are found to follow an Arrhenius type behavior and the difference in translational activation energy between free and associated ions is determined to be 9.3 ± 0.9 kJ/mol.
authors.affiliation: Soft Matter Physics Research Group, School of Physics and Astronomy, University of Leeds , Leeds, LS2 9JT, United Kingdom.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Ries
authors.forename: Asanah
authors.initials: A
authors.lastname: Radhi
authors.forename: Alice S
authors.initials: AS
authors.lastname: Keating
authors.forename: Owen
authors.initials: O
authors.lastname: Parker
authors.forename: Tatiana
authors.initials: T
authors.lastname: Budtova
mesh_terms: D002236:Carbohydrate Conformation; D002475:Cellobiose / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D004058:Diffusion; D005947:Glucose / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D012996:Solutions
chemical_list: D007093:Imidazoles; D012996:Solutions; D002475:Cellobiose; D002482:Cellulose; D005947:Glucose; C518739:1-ethyl-3-methylimidazolium