Dissolution of cellulose in alkali : A competition between ionization and hydrophobic interactions.
(2025) In Journal of Molecular Liquids 436.- Abstract
Dissolution is a key factor in better utilization of cellulose, the most abundant macromolecule on our planet. Several non-aqueous solvent systems, of very different nature, have been found to dissolve significant amounts of cellulose. For reasons of cost, safety and environment, however, water-based systems would have high priority. Cellulose is insoluble in water, but since well above 100 years, it has been observed that the combination of high pH and low temperatures provides solvent conditions with a high aqueous solubility of cellulose. The driving force of dissolution is related to the ionization of cellulose due to a deprotonation of glucose hydroxyl groups. This was qualitatively understood in early work, but in more... (More)
Dissolution is a key factor in better utilization of cellulose, the most abundant macromolecule on our planet. Several non-aqueous solvent systems, of very different nature, have been found to dissolve significant amounts of cellulose. For reasons of cost, safety and environment, however, water-based systems would have high priority. Cellulose is insoluble in water, but since well above 100 years, it has been observed that the combination of high pH and low temperatures provides solvent conditions with a high aqueous solubility of cellulose. The driving force of dissolution is related to the ionization of cellulose due to a deprotonation of glucose hydroxyl groups. This was qualitatively understood in early work, but in more contemporary literature the interactions behind the resistance to dissolution have been left more open. Recently it has been found that the insolubility of cellulose in water is due to hydrophobic interactions, which are strong due to the amphiphilic character of cellulose. The hydrophobic interaction decreases significantly with decreasing temperature. There is in addition an increase in pH as the temperature is decreased at a given NaOH concentration. A thermodynamic analysis is presented, based on the balance between ionization and a temperature dependent hydrophobic interaction. The analysis is found to explain the observed features of cellulose dissolution, including a classical phase diagram.
(Less)
- author
- Wennerström, Håkan LU and Lindman, Björn LU
- organization
- publishing date
- 2025-10
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Alkali, Cellulose dissolution, Cellulose ionization, Hydrophobic interactions, Temperature dependence
- in
- Journal of Molecular Liquids
- volume
- 436
- article number
- 128169
- publisher
- Elsevier
- external identifiers
-
- scopus:105012123589
- ISSN
- 0167-7322
- DOI
- 10.1016/j.molliq.2025.128169
- language
- English
- LU publication?
- yes
- id
- 760935e8-be69-4085-a5b1-ca4afaa2afe9
- date added to LUP
- 2025-10-27 12:09:24
- date last changed
- 2025-10-27 12:10:26
@article{760935e8-be69-4085-a5b1-ca4afaa2afe9,
abstract = {{<p>Dissolution is a key factor in better utilization of cellulose, the most abundant macromolecule on our planet. Several non-aqueous solvent systems, of very different nature, have been found to dissolve significant amounts of cellulose. For reasons of cost, safety and environment, however, water-based systems would have high priority. Cellulose is insoluble in water, but since well above 100 years, it has been observed that the combination of high pH and low temperatures provides solvent conditions with a high aqueous solubility of cellulose. The driving force of dissolution is related to the ionization of cellulose due to a deprotonation of glucose hydroxyl groups. This was qualitatively understood in early work, but in more contemporary literature the interactions behind the resistance to dissolution have been left more open. Recently it has been found that the insolubility of cellulose in water is due to hydrophobic interactions, which are strong due to the amphiphilic character of cellulose. The hydrophobic interaction decreases significantly with decreasing temperature. There is in addition an increase in pH as the temperature is decreased at a given NaOH concentration. A thermodynamic analysis is presented, based on the balance between ionization and a temperature dependent hydrophobic interaction. The analysis is found to explain the observed features of cellulose dissolution, including a classical phase diagram.</p>}},
author = {{Wennerström, Håkan and Lindman, Björn}},
issn = {{0167-7322}},
keywords = {{Alkali; Cellulose dissolution; Cellulose ionization; Hydrophobic interactions; Temperature dependence}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{Journal of Molecular Liquids}},
title = {{Dissolution of cellulose in alkali : A competition between ionization and hydrophobic interactions.}},
url = {{http://dx.doi.org/10.1016/j.molliq.2025.128169}},
doi = {{10.1016/j.molliq.2025.128169}},
volume = {{436}},
year = {{2025}},
}