Yuan, Q, Collins, S, Poole, J et al. (2 more authors) (2022) Critical role of chemical potential to assure effective encapsulation. Journal of Colloid and Interface Science, 623. pp. 86-95. ISSN 0021-9797
Abstract
Hypothesis
In emulsification-polymerisation avoiding monomer escape from emulsion droplets is the key to successful encapsulation. So far, it is believed that (1) a hydrophobe needs to be included and (2) free-micelles of surfactant need to be depleted. However, these criteria do not always work. The paper explores the critical role of the chemical potential difference between the inside and outside of the emulsion droplet for successful encapsulation.
Experiments
Crossflow membrane emulsification was used to produce uniform droplets of 1–2 µm of solutions of 3-iodoprop-2-yn-1-yl butylcarbamate (a biocide), castor oil (hydrophobe) in methyl 2-methylprop-2-enoate (monomer) into aqueous solutions with a large amount of free-micelles of surfactant. The encapsulation was followed by polymerisation. The size distribution of microcapsule from different formula were examined.
Findings
The biocide encapsulation depends on castor oil content: >12% (full); 6–12% (either full or partial); <6% (minor). Results show a critical molar fraction ratio of the monomer in the droplet to water in the aqueous phase that provides a definitive criterion to assure size retention and full encapsulation. This critical value corresponds to an energy barrier of 116 J/mol to prevent the monomer escaping. This finding is proposed to be used as an advanced rule to guide precision formulation for desired microencapsulation.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2022 Published by Elsevier Inc. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) |
Keywords: | Chemical potential; Polymerisation-encapsulation; Castor oil; Hydrophobe; Membrane emulsification |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 16 May 2022 12:58 |
Last Modified: | 25 Jun 2023 22:59 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.jcis.2022.05.014 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:186808 |