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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Dependence of cellulose dissolution in quaternary ammonium-based ionic liquids/DMSO on the molecular structure of the electrolyte

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Author(s):
Kostag, Marc [1] ; El Seoud, Omar A. [1]
Total Authors: 2
Affiliation:
[1] Univ Sao Paulo, Inst Chem, Ave Prof Lineu Prestes 748, BR-05508000 Sao Paulo, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Carbohydrate Polymers; v. 205, p. 524-532, FEB 1 2019.
Web of Science Citations: 4
Abstract

We synthesized a series of quaternary ammonium acetates (QAAcOs) and assessed their solutions in DMSO as cellulose solvents. NBz111AcO/DMSO did not dissolve cellulose; substitution of its methyl groups resulted in efficient cellulose solvents; NBz31AcO/DMSO dissolved cellulose with difficulty. We attribute the inefficiency of both QAAcOs to: strong anion-cation interactions, NBz111AcO; steric effects and cation-cation hydrophobic interactions, NBz31AcO. Using isothermal titration calorimetry, we determined the enthalpies (H-E) of QAAcO (endothermic) dissolution, and QAAcO/cellobiose (exothermic) interactions; both in dimethyl sulfoxide/acetonitrile. The ratios of H-E are 5.34:1:1.45, for NB111AcO, NA12Bz1AcO, and NBz31AcO, respectively, i.e., dissolution of the first and third QAAcO in the solvent requires more energy. The corresponding ratios for QAAcO interaction with cellobiose are: 0.74:1:0.79, i.e., the second QAAcO interacts more strongly with cellobiose. This order of solvent efficiency is corroborated by SEM images of regenerated cotton linters. Light scattering showed that dissolved cellulose can be regenerated as nanoparticles by dialysis. {[}GRAPHICS] . (AU)

FAPESP's process: 14/22136-4 - Use of green solvents and their mixtures for optimizing chemical processes
Grantee:Omar Abou El Seoud
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 16/22869-7 - Novel solvents in cellulose chemistry: synthesis, properties, and application of quaternaryammonium electrolytes for dissolution, regeneration, and derivatization of cellulose
Grantee:Marc Kostag
Support Opportunities: Scholarships in Brazil - Post-Doctoral