The University of Southampton
University of Southampton Institutional Repository

Wall repulsion of charged colloidal particles during electrophoresis in microfluidic channels

Wall repulsion of charged colloidal particles during electrophoresis in microfluidic channels
Wall repulsion of charged colloidal particles during electrophoresis in microfluidic channels
Electrophoresis describes the motion of charged particles suspended in electrolytes when subjected to an external electric field. Previous experiments have shown that particles undergoing electrophoresis are repelled from nearby channel walls, contrary to the standard description of electrophoresis that predicts no hydrodynamic repulsion. Dielectrophoretic (DEP) repulsive forces have been commonly invoked as the cause of this wall repulsion. We show that DEP forces can only account for this wall repulsion at high frequencies of applied electric field. In the presence of a low-frequency field, quadrupolar electro-osmotic flows are observed around the particles. We experimentally demonstrate that these hydrodynamic flows are the cause of the widely observed particle-wall interaction. This hydrodynamic wall repulsion should be considered in the design and application of electric-field-driven manipulation of particles in microfluidic devices.
1079-7114
Fernandez-Mateo, Raul
f287538e-c53c-4208-b8bf-945b0966fd5f
Calero, Víctor
4c270680-a83d-4c15-9cc6-df3fd34b79df
Morgan, Hywel
de00d59f-a5a2-48c4-a99a-1d5dd7854174
Garcia-Sanchez, Pablo
11cec08e-0384-4ef6-a1b3-183c9b32c4ea
Ramos, Antonio
79d60433-0c6b-4eaa-80ac-e2f61e704f72
Fernandez-Mateo, Raul
f287538e-c53c-4208-b8bf-945b0966fd5f
Calero, Víctor
4c270680-a83d-4c15-9cc6-df3fd34b79df
Morgan, Hywel
de00d59f-a5a2-48c4-a99a-1d5dd7854174
Garcia-Sanchez, Pablo
11cec08e-0384-4ef6-a1b3-183c9b32c4ea
Ramos, Antonio
79d60433-0c6b-4eaa-80ac-e2f61e704f72

Fernandez-Mateo, Raul, Calero, Víctor, Morgan, Hywel, Garcia-Sanchez, Pablo and Ramos, Antonio (2022) Wall repulsion of charged colloidal particles during electrophoresis in microfluidic channels. Physical Review Letters, 128 (7), [074501]. (doi:10.1103/PhysRevLett.128.074501).

Record type: Article

Abstract

Electrophoresis describes the motion of charged particles suspended in electrolytes when subjected to an external electric field. Previous experiments have shown that particles undergoing electrophoresis are repelled from nearby channel walls, contrary to the standard description of electrophoresis that predicts no hydrodynamic repulsion. Dielectrophoretic (DEP) repulsive forces have been commonly invoked as the cause of this wall repulsion. We show that DEP forces can only account for this wall repulsion at high frequencies of applied electric field. In the presence of a low-frequency field, quadrupolar electro-osmotic flows are observed around the particles. We experimentally demonstrate that these hydrodynamic flows are the cause of the widely observed particle-wall interaction. This hydrodynamic wall repulsion should be considered in the design and application of electric-field-driven manipulation of particles in microfluidic devices.

Text
Wall_Repulsion_in_Electrophoresis__AcceptedManuscript - Accepted Manuscript
Download (3MB)
Text
PhysRevLett.128.074501 - Version of Record
Restricted to Repository staff only
Request a copy

More information

Accepted/In Press date: 18 January 2022
Published date: 16 February 2022
Additional Information: Funding Information: V. C., P. G. S., and A. R. acknowledge Grant PGC2018-099217-B-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe.” Publisher Copyright: © 2022 American Physical Society.

Identifiers

Local EPrints ID: 456541
URI: http://eprints.soton.ac.uk/id/eprint/456541
ISSN: 1079-7114
PURE UUID: 689686fa-a6c8-4dad-9445-8aef14a24c80
ORCID for Raul Fernandez-Mateo: ORCID iD orcid.org/0000-0003-1413-8046
ORCID for Hywel Morgan: ORCID iD orcid.org/0000-0003-4850-5676

Catalogue record

Date deposited: 04 May 2022 17:18
Last modified: 06 Jun 2024 01:42

Export record

Altmetrics

Contributors

Author: Raul Fernandez-Mateo ORCID iD
Author: Víctor Calero
Author: Hywel Morgan ORCID iD
Author: Pablo Garcia-Sanchez
Author: Antonio Ramos

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×