Imperial College London
Alternate

Professor Koon-Yang Lee

Faculty of Engineering, Department of Aeronautics

Professor in Polymer Engineering
 
 
 
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Contact

 

+44 (0)20 7594 5150koonyang.lee

 
 
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Location

 

325City and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Yang:2021:10.1039/D1RA04190H,
author = {Yang, Y and Wloch, D and Lee, K-Y},
doi = {10.1039/D1RA04190H},
journal = {RSC Advances: an international journal to further the chemical sciences},
pages = {28352--28360},
title = {TEMPO-oxidised nanocellulose hydrogels and self-standing films derived from bacterial cellulose nanopaper},
url = {http://dx.doi.org/10.1039/D1RA04190H},
volume = {11},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Hydrogels derived from TEMPO-oxidised cellulose nanofibrils (TOCNs) are not robust and inherently water unstable if theTOCNs are not crosslinked or coated with a water-swellable polymer. Furthermore, the manufacturing of self-standing TOCNfilms is still a challenge due to the small TOCN diameter and viscosifying effect. Here, we report the TEMPO-mediatedoxidation of bacterial cellulose (BC) nanopaper as a route to produce robust and water stable TOCN hydrogel without theneed for additional additives or crosslinking steps, as well as self-standing TOCN films without the need for vacuum filtrationor slow-drying of TOCN suspension. Pristine BC pellicle was first press-dried into a dried and well-consolidated BC nanopaper,followed by TEMPO-oxidation at various NaClO concentrations. The oxidation reaction introduced carboxylate moieties ontoexposed BC nanofibrils within the nanopaper network structure. This then led to the swelling of the nanopaper into ahydrogel. A swelling ratio of up to 100 times the original thickness of BC nanopaper was observed upon TEMPO-oxidation.The water retention value of the TEMPO-oxidised BC hydrogels was also found to increase with increasing carboxylatecontent. These TEMPO-oxidised BC hydrogels were found to be robust and water-stable, even under prolonged (>1 month)magnetic stirring in water. We further showed that high grammage self-standing TOCN films (100 g m-2) can be fabricatedas simple as press-drying a water stable TEMPO-oxidised BC hydrogels without the need of vacuum-assisted filtration orslow-drying, which is typically the rate-limiting step in the manufacturing of self-standing TOCN films.
AU  - Yang,Y
AU  - Wloch,D
AU  - Lee,K-Y
DO  - 10.1039/D1RA04190H
EP  - 28360
PY  - 2021///
SN  - 2046-2069
SP  - 28352
TI  - TEMPO-oxidised nanocellulose hydrogels and self-standing films derived from bacterial cellulose nanopaper
T2  - RSC Advances: an international journal to further the chemical sciences
UR  - http://dx.doi.org/10.1039/D1RA04190H
UR  - https://pubs.rsc.org/en/content/articlelanding/2021/RA/D1RA04190H
UR  - http://hdl.handle.net/10044/1/91102
VL  - 11
ER  -
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