Ries, ME orcid.org/0000-0002-8050-3200, Radhi, A, Green, SM orcid.org/0000-0002-1249-6950 et al. (2 more authors) (2018) Microscopic and Macroscopic Properties of Carbohydrate Solutions in the Ionic Liquid 1-Ethyl-3-methyl-imidazolium Acetate. Journal of Physical Chemistry B, 122 (37). pp. 8763-8771. ISSN 1520-6106
Abstract
Solutions of glucose, cellobiose, and microcrystalline cellulose in the ionic liquid 1-ethyl-3-methyl-imidazolium acetate ([C2mim][OAc]) have been examined using low-field (20 MHz) NMR relaxometry and rheology. The spin–lattice (T1) and spin–spin (T2) relaxation times have been determined from 30 to 70 °C inclusive, for a range of concentrations (0–15 wt %) of each carbohydrate in [C2mim][OAc]. The zero shear rate viscosities for the same samples across the same temperature range were studied. The viscosity, NMR relaxometry, and previously published diffusion data were all analyzed together through the Debye–Stokes–Einstein equations. Microscopically, these systems behave as an “ideal mixture” of free ions and ions associated with the carbohydrate molecules. The molar ratio of carbohydrate OH groups to ionic liquid molecules, α, is the key parameter in determining the NMR relaxometry and hence the local microscopic environment of the ions. NMR relaxometry data are found to follow an Arrhenius type behavior, and the difference in rotational activation energy between free and associated ions is determined at 6.2 ± 0.5 kJ/mol.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2018 American Chemical Society. ACS AuthorChoice - This is an open access article published under a Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited. |
Keywords: | ionic liquid; cellulose; glucose; cellobiose; NMR; Relaxometry |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Soft Matter Physics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 16 Oct 2018 15:25 |
Last Modified: | 16 Oct 2018 15:25 |
Status: | Published |
Publisher: | American Chemical Society |
Identification Number: | 10.1021/acs.jpcb.8b06939 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:137125 |