Thompson, K.L., Derry, M.J. orcid.org/0000-0001-5010-6725, Hatton, F.L. orcid.org/0000-0002-0105-7530 et al. (1 more author) (2018) Long-term stability of n-alkane-in-water Pickering nanoemulsions: effect of aqueous solubility of droplet phase on Ostwald ripening. Langmuir, 34 (31). pp. 9289-9297. ISSN 0743-7463
Abstract
High-pressure microfluidization is used to prepare a series of oil-in-water Pickering nanoemulsions using sterically-stabilized diblock copolymer nanoparticles as the Pickering emulsifier. The droplet phase comprised either n-octane, n-decane, n-dodecane, or n-tetradecane. This series of oils enabled the effect of aqueous solubility on Ostwald ripening to be studied, which is the primary instability mechanism for such nanoemulsions. Analytical centrifugation (LUMiSizer instrument) was used to evaluate the long-term stability of these Pickering nanoemulsions over time scales of weeks/months. This technique enables convenient quantification of the fraction of growing oil droplets and confirmed that using n-octane (aqueous solubility = 0.66 mg dm-3 at 20 °C) leads to instability even over relatively short time periods. However, using n-tetradecane (aqueous solubility = 0.386 μg dm-3 at 20 °C) leads to significantly improved long-term stability with respect to Ostwald ripening, with all droplets remaining below 1 μm diameter after 6 weeks storage at 20 °C. In the case of n-dodecane, the long-term stability of these new copolymer-stabilized Pickering nanoemulsions is significantly better than the silica-stabilized Pickering nanoemulsions reported in the literature by Persson et al. ( Colloids Surf., A, 2014, 459, 48-57). This is attributed to a much greater interfacial yield stress for the former system, as recently described in the literature (see P. J. Betramo et al. Proc. Natl. Acad. Sci. U.S.A., 2017, 114, 10373-10378).
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2018 American Chemical Society. This is an open access article published under a Creative Commons Attribution (CC-BY) (https://creativecommons.org/licenses/by/4.0/) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Chemistry (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 06 Aug 2018 09:45 |
Last Modified: | 20 Aug 2020 11:05 |
Status: | Published |
Publisher: | American Chemical Society |
Refereed: | Yes |
Identification Number: | 10.1021/acs.langmuir.8b01835 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:134150 |