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Monovalent salt and pH-induced gelation of oxidized cellulose nanofibrils and starch networks : Combining rheology and small-angle X-Ray scattering

Hossain, Kazi M. Zakir ; Calabrese, Vincenzo ; da Silva, Marcelo A. ; Bryant, Saffron J. ; Schmitt, Julien LU ; Ahn-Jarvis, Jennifer H. ; Warren, Frederick J. ; Khimyak, Yaroslav Z. ; Scott, Janet L. and Edler, Karen J. LU orcid (2021) In Polymers 13(6).
Abstract

Water quality parameters such as salt content and various pH environments can alter the stability of gels as well as their rheological properties. Here, we investigated the effect of various concentrations of NaCl and different pH environments on the rheological properties of TEMPOoxidised cellulose nanofibril (OCNF) and starch-based hydrogels. Addition of NaCl caused an increased stiffness of the OCNF:starch (1:1 wt%) blend gels, where salt played an important role in reducing the repulsive OCNF fibrillar interactions. The rheological properties of these hydrogels were unchanged at pH 5.0 to 9.0. However, at lower pH (4.0), the stiffness and viscosity of the OCNF and OCNF:starch gels appeared to increase due to proton-induced fibrillar... (More)

Water quality parameters such as salt content and various pH environments can alter the stability of gels as well as their rheological properties. Here, we investigated the effect of various concentrations of NaCl and different pH environments on the rheological properties of TEMPOoxidised cellulose nanofibril (OCNF) and starch-based hydrogels. Addition of NaCl caused an increased stiffness of the OCNF:starch (1:1 wt%) blend gels, where salt played an important role in reducing the repulsive OCNF fibrillar interactions. The rheological properties of these hydrogels were unchanged at pH 5.0 to 9.0. However, at lower pH (4.0), the stiffness and viscosity of the OCNF and OCNF:starch gels appeared to increase due to proton-induced fibrillar interactions. In contrast, at higher pH (11.5), syneresis was observed due to the formation of denser and aggregated gel networks. Interactions as well as aggregation behaviour of these hydrogels were explored via ζ-potential measurements. Furthermore, the nanostructure of the OCNF gels was probed using small-angle x-ray scattering (SAXS), where the SAXS patterns showed an increase of slope in the low-q region with increasing salt concentration arising from aggregation due to the screening of the surface charge of the fibrils.

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author
; ; ; ; ; ; ; ; and
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Cellulose nanofibrils, pH, Rheology, Salt, SAXS, Starch
in
Polymers
volume
13
issue
6
article number
951
pages
17 pages
publisher
MDPI AG
external identifiers
  • scopus:85103092606
  • pmid:33808830
ISSN
2073-4360
DOI
10.3390/polym13060951
language
English
LU publication?
no
additional info
Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
id
1c3a4ce3-e27e-454b-84f2-e1fe3e1cbf1e
date added to LUP
2022-07-12 15:39:31
date last changed
2024-06-11 14:11:28
@article{1c3a4ce3-e27e-454b-84f2-e1fe3e1cbf1e,
  abstract     = {{<p>Water quality parameters such as salt content and various pH environments can alter the stability of gels as well as their rheological properties. Here, we investigated the effect of various concentrations of NaCl and different pH environments on the rheological properties of TEMPOoxidised cellulose nanofibril (OCNF) and starch-based hydrogels. Addition of NaCl caused an increased stiffness of the OCNF:starch (1:1 wt%) blend gels, where salt played an important role in reducing the repulsive OCNF fibrillar interactions. The rheological properties of these hydrogels were unchanged at pH 5.0 to 9.0. However, at lower pH (4.0), the stiffness and viscosity of the OCNF and OCNF:starch gels appeared to increase due to proton-induced fibrillar interactions. In contrast, at higher pH (11.5), syneresis was observed due to the formation of denser and aggregated gel networks. Interactions as well as aggregation behaviour of these hydrogels were explored via ζ-potential measurements. Furthermore, the nanostructure of the OCNF gels was probed using small-angle x-ray scattering (SAXS), where the SAXS patterns showed an increase of slope in the low-q region with increasing salt concentration arising from aggregation due to the screening of the surface charge of the fibrils.</p>}},
  author       = {{Hossain, Kazi M. Zakir and Calabrese, Vincenzo and da Silva, Marcelo A. and Bryant, Saffron J. and Schmitt, Julien and Ahn-Jarvis, Jennifer H. and Warren, Frederick J. and Khimyak, Yaroslav Z. and Scott, Janet L. and Edler, Karen J.}},
  issn         = {{2073-4360}},
  keywords     = {{Cellulose nanofibrils; pH; Rheology; Salt; SAXS; Starch}},
  language     = {{eng}},
  month        = {{03}},
  number       = {{6}},
  publisher    = {{MDPI AG}},
  series       = {{Polymers}},
  title        = {{Monovalent salt and pH-induced gelation of oxidized cellulose nanofibrils and starch networks : Combining rheology and small-angle X-Ray scattering}},
  url          = {{http://dx.doi.org/10.3390/polym13060951}},
  doi          = {{10.3390/polym13060951}},
  volume       = {{13}},
  year         = {{2021}},
}