Gregory, D.A. orcid.org/0000-0003-2489-5462 and Ebbens, S.J. orcid.org/0000-0002-4727-4426 (2018) Symmetrical Catalytically Active Colloids Collectively Induce Convective Flow. Langmuir, 34 (14). pp. 4307-4313. ISSN 0743-7463
Abstract
Although much attention has focused on self-motile asymmetrical catalytically active “Janus” colloids as a route to enable new fluidic transport applications, the motion of symmetrical catalytically active colloids is less investigated. This is despite isotropically active colloids being more accessible and commonly used as supports for heterogeneous catalysis. Here, we addressed this by systematically investigating the motion of platinum-coated colloids capable of isotropically decomposing hydrogen peroxide. We observed the onset of collective convective flow as the colloidal volume fraction increased above a threshold. The ballistic velocities induced by the collective flow were quantified by particle tracking and were found to increase with the volume fraction. We also determined the associated increase in the Péclet number as evidence of the potential to use convection as a simple method to enhance mass transport rates. By determining the persistence lengths, we were able to correlate the magnitude of convective flow with the overall catalytic activity per unit volume. This suggests that the mechanism for the collective flow is driven by chemical activity-induced local density differences. Finally, we discussed these results in the context of potential new fluidic applications and highlighted the role that activity-induced convection may play in experiments designed to investigate self-motile catalytic systems.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | This document is the Accepted Manuscript version of a Published Work that appeared in final form in Langmuir, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.langmuir.8b00310. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Chemical and Biological Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 31 May 2018 14:32 |
Last Modified: | 21 Mar 2019 01:41 |
Published Version: | https://doi.org/10.1021/acs.langmuir.8b00310 |
Status: | Published |
Publisher: | American Chemical Society |
Refereed: | Yes |
Identification Number: | 10.1021/acs.langmuir.8b00310 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:131131 |