Rashid, A, Vakurov, A and Nelson, A (2018) Phospholipid bilayers at the mercury (Hg)/water interface. Electrochimica Acta, 281. pp. 152-161. ISSN 0013-4686
Abstract
This study reports on the electrochemical characterisation of dioleoyl phospatidylcholine (DOPC) bilayer structures on a negatively polarised mercury (Hg) electrode. The bilayers are stable on the Hg surface between −1.0 and −1.3 V applied potential. The experimental approaches were:- (i) rapid cyclic voltammetry (RCV) to “fingerprint” the bilayers, (ii) potential step experiments to record Zn²+ reduction and, (iii) electrochemical impedance. The results show the following. Both the specific capacitance (5 μF cm‾²) and the specific resistance of the bilayer are higher and lower respectively than that of a defect-free free standing DOPC bilayer. This indicates the presence of water and ions in the bilayer within an applied negative field. The bilayer's resistance to electrolyte movement decreases with increase in negative potential to a minimum at −1.3 V. The DOPC bilayer is less permeable to Zn²+ ions compared to the DOPC monolayer coated electrode at applied negative potentials and its permeability to Zn²+ increases with an increase in negative applied potential. The specific capacitance of the bilayer increases to about 7.5 μF cm‾² with increase in applied negative potential showing the increasing significance of water in the bilayer commensurate with its increased permeability to ions. Adsorption of SiO₂ nanoparticles on the bilayer surface causes a step negative potential shift in the anodic capacitance current bilayer reformation peak indicating an acceleration of the bilayer reformation process.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | Crown Copyright © 2018 Published by Elsevier Ltd. All rights reserved. This is an author produced version of a paper published in Electrochimica Acta. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | DOPC bilayers; Hg; Negative applied potential; Zn2+ chronoamperometry; Electrochemical impedance |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) > Physical Chemistry (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 11 Jun 2018 16:41 |
Last Modified: | 23 May 2019 00:43 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.electacta.2018.05.141 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:131805 |