Unravelling cationic cellulose nanofibril hydrogel structure : NMR spectroscopy and small angle neutron scattering analyses
Courtenay, James C. ; Ramalhete, Susana M. ; Skuze, William J. ; Soni, Rhea ; Khimyak, Yaroslav Z. ; Edler, Karen J. LU
and Scott, Janet L.
(2018)
In Soft Matter
14(2).
p.255-263
- Abstract
Stiff, elastic, viscous shear thinning aqueous gels are formed upon dispersion of low weight percent concentrations of cationically modified cellulose nanofibrils (CCNF) in water. CCNF hydrogels produced from cellulose modified with glycidyltrimethylammonium chloride, with degree of substitution (DS) in the range 10.6(3)-23.0(9)%, were characterised using NMR spectroscopy, rheology and small angle neutron scattering (SANS) to probe the fundamental form and dimensions of the CCNF and to reveal interfibrillar interactions leading to gelation. As DS increased CCNF became more rigid as evidenced by longer Kuhn lengths, 18-30 nm, derived from fitting of SANS data to an elliptical cross-section, cylinder model. Furthermore, apparent changes... (More)
Stiff, elastic, viscous shear thinning aqueous gels are formed upon dispersion of low weight percent concentrations of cationically modified cellulose nanofibrils (CCNF) in water. CCNF hydrogels produced from cellulose modified with glycidyltrimethylammonium chloride, with degree of substitution (DS) in the range 10.6(3)-23.0(9)%, were characterised using NMR spectroscopy, rheology and small angle neutron scattering (SANS) to probe the fundamental form and dimensions of the CCNF and to reveal interfibrillar interactions leading to gelation. As DS increased CCNF became more rigid as evidenced by longer Kuhn lengths, 18-30 nm, derived from fitting of SANS data to an elliptical cross-section, cylinder model. Furthermore, apparent changes in CCNF cross-section dimensions suggested an "unravelling" of initially twisted fibrils into more flattened ribbon-like forms. Increases in elastic modulus (7.9-62.5 Pa) were detected with increased DS and 1H solution-state NMR T1 relaxation times of the introduced surface -N+(CH3)3 groups were found to be longer in hydrogels with lower DS, reflecting the greater flexibility of the low DS CCNF. This is the first time that such correlation between DS and fibrillar form and stiffness has been reported for these potentially useful rheology modifiers derived from renewable cellulose.
(Less)
- author
- Courtenay, James C.
; Ramalhete, Susana M.
; Skuze, William J.
; Soni, Rhea
; Khimyak, Yaroslav Z.
; Edler, Karen J.
LU
and Scott, Janet L.
- publishing date
- 2018
- type
- Contribution to journal
- publication status
- published
- in
- Soft Matter
- volume
- 14
- issue
- 2
- pages
- 9 pages
- publisher
- Royal Society of Chemistry
- external identifiers
-
- pmid:29238786
- scopus:85040169378
- ISSN
- 1744-683X
- DOI
- 10.1039/c7sm02113e
- language
- English
- LU publication?
- no
- additional info
- Publisher Copyright: © 2018 The Royal Society of Chemistry.
- id
- 47bc8399-a455-4c1c-b8a3-64bd106ead33
- date added to LUP
- 2023-01-18 09:13:18
- date last changed
- 2024-05-16 12:33:33
@article{47bc8399-a455-4c1c-b8a3-64bd106ead33,
abstract = {{<p>Stiff, elastic, viscous shear thinning aqueous gels are formed upon dispersion of low weight percent concentrations of cationically modified cellulose nanofibrils (CCNF) in water. CCNF hydrogels produced from cellulose modified with glycidyltrimethylammonium chloride, with degree of substitution (DS) in the range 10.6(3)-23.0(9)%, were characterised using NMR spectroscopy, rheology and small angle neutron scattering (SANS) to probe the fundamental form and dimensions of the CCNF and to reveal interfibrillar interactions leading to gelation. As DS increased CCNF became more rigid as evidenced by longer Kuhn lengths, 18-30 nm, derived from fitting of SANS data to an elliptical cross-section, cylinder model. Furthermore, apparent changes in CCNF cross-section dimensions suggested an "unravelling" of initially twisted fibrils into more flattened ribbon-like forms. Increases in elastic modulus (7.9-62.5 Pa) were detected with increased DS and <sup>1</sup>H solution-state NMR T<sub>1</sub> relaxation times of the introduced surface -N<sup>+</sup>(CH<sub>3</sub>)<sub>3</sub> groups were found to be longer in hydrogels with lower DS, reflecting the greater flexibility of the low DS CCNF. This is the first time that such correlation between DS and fibrillar form and stiffness has been reported for these potentially useful rheology modifiers derived from renewable cellulose.</p>}},
author = {{Courtenay, James C. and Ramalhete, Susana M. and Skuze, William J. and Soni, Rhea and Khimyak, Yaroslav Z. and Edler, Karen J. and Scott, Janet L.}},
issn = {{1744-683X}},
language = {{eng}},
number = {{2}},
pages = {{255--263}},
publisher = {{Royal Society of Chemistry}},
series = {{Soft Matter}},
title = {{Unravelling cationic cellulose nanofibril hydrogel structure : NMR spectroscopy and small angle neutron scattering analyses}},
url = {{http://dx.doi.org/10.1039/c7sm02113e}},
doi = {{10.1039/c7sm02113e}},
volume = {{14}},
year = {{2018}},
}