, Volume 25, Issue 1, pp 137–150 | Cite as

Understanding the interactions of cellulose fibres and deep eutectic solvent of choline chloride and urea

  • Tiia-Maria Tenhunen
  • Anna E. Lewandowska
  • Hannes Orelma
  • Leena-Sisko Johansson
  • Tommi Virtanen
  • Ali Harlin
  • Monika Österberg
  • Stephen J. Eichhorn
  • Tekla TammelinEmail author
Original Paper


A deep eutectic solvent composed of choline chloride (ChCl) and urea has been recently introduced as a promising cellulose compatible medium that enables e.g. fibre spinning. This paper clarifies the influence of such a solvent system on the structure and chemical composition of the cellulosic pulp fibres. Special emphasis was placed on the probable alterations of the chemical composition due to the dissolution of the fibre components and/or due to the chemical derivatisation taking place during the DES treatment. Possible changes in fibre morphology were studied with atomic force microscopy and scanning electron microscopy. Chemical compositions of pulp fibres were determined from the carbohydrate content, and by analysing the elemental content. Detailed structural characterisation of the fibres was carried out using spectroscopic methods; namely X-Ray Photoelectron Spectroscopy, solid state Nuclear Magnetic Resonance and Raman Spectroscopy. No changes with respect to fibre morphology were revealed and negligible changes in the carbohydrate composition were noted. The most significant change was related to the nitrogen content of the pulp after the DES treatment. Comprehensive examination using spectroscopic methods revealed that the nitrogen originated from strongly bound ChCl residuals that could not be removed with a mild ethanol washing procedure. According to Raman spectroscopic data and methylene blue adsorption tests, the cationic groups of ChCl seems to be attached to the anionic groups of pulp by electrostatic forces. These findings will facilitate the efficient utilisation of DES as a cellulose compatible medium without significantly affecting the native fibre structure.


Deep eutectic solvent Urea Choline chloride DES Pulp 



The authors acknowledge the Finnish Funding Agency for Innovation (TEKES) for funding the work via Design Driven Value Chains in the World of Cellulose 2.0 project. The Academy of Finland (Project ID 300367) is acknowledged for enabling the research mobility of T.T. to the University of Exeter, UK. Unto Tapper (VTT) is thanked for the SEM imaging, Atte Mikkelson, Ritva Heinonen and Marita Ikonen (VTT) for the chemical analysis and Robertus Nugroho (Aalto University) for the AFM imaging.

Supplementary material

10570_2017_1587_MOESM1_ESM.docx (231 kb)
Supplementary material 1 (DOCX 230 kb)


  1. Abbott AP, Capper G, Davies DL et al (2003) Novel solvent properties of choline chloride/urea mixtures. Chem Commun 99:70–71. CrossRefGoogle Scholar
  2. Abbott AP, Bell TJ, Handa S, Stoddart B (2006) Cationic functionalisation of cellulose using a choline based ionic liquid analogue. Green Chem 8:784–786. CrossRefGoogle Scholar
  3. Agarwal UP, Reiner RS, Ralph SA (2010) Cellulose I crystallinity determination using FT-Raman spectroscopy: univariate and multivariate methods. Cellulose 17:721–733. CrossRefGoogle Scholar
  4. Akutsu H (1981) Direct determination by Raman scattering of the conformation of the choline group in phospholipid bilayers. Biochemistry 20:7359–7366. CrossRefGoogle Scholar
  5. Ardenkjaer-Larsen JH, Fridlund B, Gram A et al (2003) Increase in signal-to-noise ratio of > 10,000 times in liquid-state NMR. Proc Natl Acad Sci U S A 100:10158–10163. CrossRefGoogle Scholar
  6. Beamson G, Briggs D (1993) Cellulose spectra in high resolution XPS of organic polymers: the scienta ESCA300 database. J Chem Educ 70:A25. Google Scholar
  7. Cai J, Zhang L (2005) Rapid dissolution of cellulose in LiOH/urea and NaOH/urea aqueous solutions. Macromol Biosci 5:539–548. CrossRefGoogle Scholar
  8. Edwards HG, Farwell DW, Webster D (1997) FT Raman microscopy of untreated natural plant fibres. Spectrochim Acta A Mol Biomol Spectrosc 53A:2383–2392. CrossRefGoogle Scholar
  9. Ekman K, Eklund V, Fors J et al (1984) Regenerated cellulose fibers from cellulose carbamate solutions. Lenzing Ber 57:38–40Google Scholar
  10. Eronen P, Österberg M, Jääskeläinen A-S (2009) Effect of alkaline treatment on cellulose supramolecular structure studied with combined confocal Raman spectroscopy and atomic force microscopy. Cellulose 16:167–178. CrossRefGoogle Scholar
  11. Ershova O, da Costa EV, Fernandes AJS et al (2012) Effect of urea on cellulose degradation under conditions of alkaline pulping. Cellulose 19:2195–2204. CrossRefGoogle Scholar
  12. Fu F, Xu M, Wang H et al (2015) Improved synthesis of cellulose carbamates with minimum urea based on an easy scale-up method. ACS Sustain Chem Eng 3:1510–1517. CrossRefGoogle Scholar
  13. Gierlinger N, Schwanninger M, Reinecke A, Burgert I (2006) Molecular changes during tensile deformation of single wood fibers followed by Raman microscopy. Biomacromolecules 7:2077–2081. CrossRefGoogle Scholar
  14. Harper RJ Jr, Stone RL (1986) Cationic cotton plus easy care. Text Chem Color 18:33–35Google Scholar
  15. Ho TTT, Zimmermann T, Hauert R, Caseri W (2011) Preparation and characterization of cationic nanofibrillated cellulose from etherification and high-shear disintegration processes. Cellulose 18:1391–1406. CrossRefGoogle Scholar
  16. Johansson LS, Campbell JM (2004) Reproducible XPS on biopolymers: cellulose studies. Surf Interface Anal 36:1018–1022. CrossRefGoogle Scholar
  17. Johansson L, Tammelin T, Campbell JM et al (2011) Experimental evidence on medium driven cellulose surface adaptation demonstrated using nanofibrillated cellulose. Soft Matter 7:10917. CrossRefGoogle Scholar
  18. Keuleers R, Desseyn HO, Rousseau B, Van Alsenoy C (1999) Vibrational analysis of urea. J Phys Chem A 103:4621. CrossRefGoogle Scholar
  19. Kim JY, Choi H-M (2014) Cationization of periodate-oxidized cotton cellulose with choline chloride. Cellul Chem Technol 48:25–32Google Scholar
  20. Lahtinen P, Liukkonen S, Pere J et al (2014) A Comparative study of fibrillated fibers from different mechanical and chemical pulps. BioResources 9:2115–2127CrossRefGoogle Scholar
  21. Larsson PT, Hult E, Wickholm K et al (1999) CPrMAS 13 C-NMR spectroscopy applied to structure and interaction studies on cellulose I. Solid State Nucl Magn Reson 15:31–40. CrossRefGoogle Scholar
  22. Lewandowska AE, Soutis C, Savage L, Eichhorn SJ (2015) Carbon fibres with ordered graphitic-like aggregate structures from a regenerated cellulose fibre precursor. Compos Sci Technol 116:50–57. CrossRefGoogle Scholar
  23. Lobo HR, Singh BS, Shankarling GS (2012) Deep eutectic solvents and glycerol: a simple, environmentally benign and efficient catalyst/reaction media for synthesis of N- aryl phthalimide derivatives. Green Chem Lett Rev 5:487–533. CrossRefGoogle Scholar
  24. Palit D, Moulik SP (2000) Adsorption of methylene blue on cellulose from its own solution and its mixture with methyl orange. Indian J Chem Sect A Inorg Phys Theor Anal Chem 39:611–617Google Scholar
  25. Park JH, Oh KW, Choi HM (2013) Preparation and characterization of cotton fabrics with antibacterial properties treated by crosslinkable benzophenone derivative in choline chloride-based deep eutectic solvents. Cellulose 20:2101–2114. CrossRefGoogle Scholar
  26. Samanta AK, Kar TR, Mukhopadhyay A et al (2015) Studies on dyeing process variables for salt free reactive dyeing of glycine modified cationized cotton muslin fabric. J Inst Eng Ser E 96:31–44. CrossRefGoogle Scholar
  27. Segal L, Eggerton FV (1961) Some aspects of the reaction between urea and cellulose. Text Res J 31:460–471CrossRefGoogle Scholar
  28. Sirviö JA, Visanko M, Liimatainen H (2015) Deep eutectic solvent system based on choline chloride-urea as a pre-treatment for nanofibrillation of wood cellulose. Green Chem 17:3401–3406. CrossRefGoogle Scholar
  29. Sluiter A, Hames B, Ruiz R et al (2012) NREL/TP-510-42618 analytical procedure—determination of structural carbohydrates and lignin in Biomass. Lab Anal Proced 17Google Scholar
  30. Suchy M, Hakala T, Kangas H et al (2009) Effects of commercial cellobiohydrolase treatment on fiber strength and morphology of bleached hardwood pulp. Holzforschung 63:731–736. CrossRefGoogle Scholar
  31. Suopajärvi T, Sirviö JA, Liimatainen H (2017) Nanofibrillation of deep eutectic solvent-treated paper and board cellulose pulps. Carbohydr Polym 169:167–175. CrossRefGoogle Scholar
  32. Swerin A, Odberg L, Lindstrbm T, Pulp S (1990) Deswelling of hardwood kraft pulp fibers by cationic polymers. Nord Pulp Pap Res J 5:188–196CrossRefGoogle Scholar
  33. Tenhunen T, Hakalahti M, Kouko J et al (2016) Method for forming pulp fiber yarns developed by a design driven process. BioResources 11:2492–2503. CrossRefGoogle Scholar
  34. Wang S, Peng X, Zhong L et al (2015) Choline chloride/urea as an effective plasticizer for production of cellulose films. Carbohydr Polym 117:133–139. CrossRefGoogle Scholar
  35. Wen Q, Chen JX, Tang YL et al (2015) Assessing the toxicity and biodegradability of deep eutectic solvents. Chemosphere 132:63–69. CrossRefGoogle Scholar
  36. Wiley JH, Atalla R (1987) Band assignments in the Raman-spectra of celluloses. Carbohydr Res 160:113–129. CrossRefGoogle Scholar
  37. Willberg-Keyriläinen P, Hiltunen J, Ropponen J (2017) Production of cellulose carbamate using urea-based deep eutectic solvents. Cellulose. Google Scholar
  38. Willför S, Pranovich A, Tamminen T et al (2009) Carbohydrate analysis of plant materials with uronic acid-containing polysaccharides-A comparison between different hydrolysis and subsequent chromatographic analytical techniques. Ind Crops Prod 29:571–580. CrossRefGoogle Scholar
  39. Xu GC, Ding JC, Han RZ et al (2016) Enhancing cellulose accessibility of corn stover by deep eutectic solvent pretreatment for butanol fermentation. Bioresour Technol 203:364–369. CrossRefGoogle Scholar
  40. Yin C, Li J, Xu Q et al (2007) Chemical modification of cotton cellulose in supercritical carbon dioxide: synthesis and characterization of cellulose carbamate. Carbohydr Polym 67:147–154. CrossRefGoogle Scholar
  41. Zhang Q, De Oliveira Vigier K, Royer S, Jerome F (2012) Deep eutectic solvents: syntheses, properties and applications. Chem Soc Rev 41:7108–7146. CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V., part of Springer Nature 2017

Authors and Affiliations

  • Tiia-Maria Tenhunen
    • 1
  • Anna E. Lewandowska
    • 2
  • Hannes Orelma
    • 1
  • Leena-Sisko Johansson
    • 3
  • Tommi Virtanen
    • 1
  • Ali Harlin
    • 1
  • Monika Österberg
    • 3
  • Stephen J. Eichhorn
    • 2
    • 4
  • Tekla Tammelin
    • 1
    Email author
  1. 1.VTT Technical Research Centre of Finland LtdEspooFinland
  2. 2.College of Engineering, Mathematics and Physical SciencesUniversity of ExeterExeterUK
  3. 3.Department of Forest Products TechnologyAalto University School of Chemical TechnologyAaltoFinland
  4. 4.Bristol Composites Institute (ACCIS)University of BristolBristolUK

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