Zhang, Z.J., Madsen, J., Warren, N.J. et al. (4 more authors) (2017) Influence of Salt on the Solution Dynamics of a Phosphorylcholine-Based Polyzwitterion. European Polymer Journal, 87. pp. 449-457. ISSN 0014-3057
Abstract
The diffusion of a polyzwitterion, poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), in aqueous solution containing different alkali halides was studied by fluorescence correlation spectroscopy at single molecule level. It was found that the halide anion has a greater effect on the radius of zwitterionic PMPC molecules than alkali cations, which is due to the mechanism by which PMPC molecules interact with the surrounding hydrogen bond network of water molecules and adsorbed ions. With the addition of salt, the size of PMPC remains constant while its diffusion coefficient is reduced slightly, although larger cations (e.g. K+) result in slightly increased diffusion coefficient for 1 M potassium chloride-based solutions. This enhanced diffusion coefficient is attributed to the decrease in the viscosity of the aqueous solution on the addition of salt. When the counter-ion was varied in potassium-based salts, different effects were observed for different anions, resulting a reduction in the diffusion coefficient as a function of salt concentration. This reduction was modest for KBr, but significant for KI. Overall, no discernible changes were observed as the size of the PMPC coil was varied, except in case of KI for which a significant increase was observed at higher ionic strength. Divalent cations (Ca2+ and Mg2+), produced similar effects to those found for monovalent cations. These effects are explained by the interaction of PMPC with the hydrogen bond network of water molecules and with the adsorbed ions.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016 Published by Elsevier Ltd. This is an author produced version of a paper subsequently published in European Polymer Journal. Uploaded in accordance with the publisher's self-archiving policy. Article available under the terms of the CC-BY-NC-ND licence (https://creativecommons.org/licenses/by-nc-nd/4.0/) |
Keywords: | Solution dynamics; diffusion; zwitterionic; phosphorylcholine; polyelectrolyte |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Funding Information: | Funder Grant number ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL (EPSRC) EP/I012060/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 06 Dec 2016 15:43 |
Last Modified: | 21 Jun 2018 00:38 |
Published Version: | https://doi.org/10.1016/j.eurpolymj.2016.12.001 |
Status: | Published |
Publisher: | Elsevier |
Refereed: | Yes |
Identification Number: | 10.1016/j.eurpolymj.2016.12.001 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:109031 |
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