Takeshita, S, Sadeghpour, A orcid.org/0000-0002-0475-7858, Sivaraman, D et al. (2 more authors) (2020) Solvents, CO2 and biopolymers: Structure formation in chitosan aerogel. Carbohydrate Polymers, 247. 116680. ISSN 0144-8617
Abstract
The functionality of biopolymer aerogels is inherently linked to its microstructure, which in turn depends on the synthesis protocol. Detailed investigations on the macroscopic size change and nanostructure formation during chitosan aerogel synthesis reveal a new aspect of biopolymer aerogels that increases process flexibility. Formaldehyde-cross-linked chitosan gels retain a significant fraction of their original volume after solvent exchange into methanol (50.3 %), ethanol (47.1 %) or isopropanol (26.7 %), but shrink dramatically during subsequent supercritical CO2 processing (down to 4.9 %, 3.5 % and 3.7 %, respectively). In contrast, chitosan gels shrink more strongly upon exchange into n-heptane (7.2 %), a low affinity solvent, and retain this volume during CO2 processing. Small-angle X-ray scattering confirms that the occurrence of the volumetric changes correlates with mesoporous network formation through physical coagulation in CO2 or n-heptane. The structure formation step can be controlled by solvent–polymer and polymer–drying interactions, which would be a new tool to tailor the aerogel structure.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 Elsevier Ltd. All rights reserved. This is an author produced version of an article published in Carbohydrate Polymers. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Aerogels; Biopolymers; Small-angle X-ray scattering; Supercritical drying |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Food Science and Nutrition (Leeds) > FSN Chemistry and Biochemistry (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 03 Sep 2021 10:47 |
Last Modified: | 03 Sep 2021 10:47 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.carbpol.2020.116680 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:177772 |