Ionization of Cellobiose in Aqueous Alkali and the Mechanism of Cellulose DissolutionShow others and affiliations
2016 (English)In: The Journal of Physical Chemistry Letters, E-ISSN 1948-7185, Vol. 7, no 24, p. 5044-5048Article in journal (Refereed) Published
Abstract [en]
Cellulose, one of the most abundant renewable resources, is insoluble in most common solvents but dissolves in aqueous alkali under a narrow range of conditions. To elucidate the solubilization mechanism, we performed electrophoretic NMR on cellobiose, a subunit of cellulose, showing that cellobiose acts as an acid with two dissociation steps at pH 12 and 13.5. Chemical shift differences between cellobiose in NaOH and NaCl were estimated using 2D NMR and compared to DFT shift differences upon deprotonation. The dissociation steps are the deprotonation of the hemiacetal OH group and the deprotonation of one of four OH groups on the nonreducing anhydroglucose unit. MD simulations reveal that aggregation is suppressed upon charging cellulose chains in solution. Our findings strongly suggest that cellulose is to a large extent charged in concentrated aqueous alkali, a seemingly crucial factor for solubilization. This insight, overlooked in the current literature, is important for understanding cellulose dissolution and for synthesis of new sustainable materials.
Place, publisher, year, edition, pages
American Chemical Society , 2016. Vol. 7, no 24, p. 5044-5048
Keywords [en]
Chemical shift, Deprotonation, Dissociation, Dissolution, Nuclear magnetic resonance spectroscopy, Solubility, Anhydroglucose unit, Cellulose chain, Cellulose dissolutions, Common solvents, Hemiacetals, MD simulation, Renewable resource, Sustainable materials, Cellulose, Cellulose Derivatives, Electrophoresis, Renewable Resources, Solvents, Synthesis
National Category
Engineering and Technology
Identifiers
URN: urn:nbn:se:ri:diva-43901DOI: 10.1021/acs.jpclett.6b02346Scopus ID: 2-s2.0-85006725083OAI: oai:DiVA.org:ri-43901DiVA, id: diva2:1394351
2020-02-182020-02-182024-07-04Bibliographically approved