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Cellulose

, Volume 21, Issue 3, pp 1183–1192 | Cite as

Dissolution of cellulose in aqueous NaOH/urea solution: role of urea

  • Bi Xiong
  • Pingping Zhao
  • Kai Hu
  • Lina Zhang
  • Gongzhen Cheng
Original Paper

Abstract

Urea can improve the solubility and stability of cellulose in aqueous alkali solution, while its role has not come to a conclusion. To reveal the role of urea in solution, NMR was introduced to investigate the interaction between urea and the other components in solution. Results from chemical shifts and longitudinal relaxation times show that: (1) urea has no strong direct interaction with cellulose as well as NaOH; (2) urea does not have much influence on the structural dynamics of water. Urea may play its role through van der Waals force. It may accumulate on the cellulose hydrophobic region to prevent dissolved cellulose molecules from re-gathering. The driving force for the self-assembly of cellulose and urea molecules might be hydrophobic interaction. In the process of cellulose dissolution, OH breaks the hydrogen bonds, Na+ hydrations stabilize the hydrophilic hydroxyl groups and urea stabilizes the hydrophobic part of cellulose.

Keywords

Urea Cellulose dissolution NMR Hydrophobic effect 

Notes

Acknowledgments

This work was supported by the National Basic Research Program of China (973 Program, 2010CB732203) and the Special Project on Development of National Key Scientific Instruments and Equipments of China (2011YQ120035).

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Copyright information

© Springer Science+Business Media Dordrecht 2014

Authors and Affiliations

  1. 1.College of Chemistry and Molecular ScienceWuhan UniversityWuhanPeople’s Republic of China

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