Bulletin of the American Physical Society
76th Annual Meeting of the Division of Fluid Dynamics
Sunday–Tuesday, November 19–21, 2023; Washington, DC
Session X14: Biofluids: Suspension/Sedimentation
8:00 AM–9:57 AM,
Tuesday, November 21, 2023
Room: 144AB
Chair: Zhouyang Ge, University of British Columbia
Abstract: X14.00008 : Superparamagnetic Colloids: Formation and Dynamics of Chains and Disk-like Clusters under External Magnetic Fields
9:31 AM–9:44 AM
Presenter:
Florence Mignolet
(University of Liege)
Authors:
Florence Mignolet
(University of Liege)
Geoffroy Lumay
(University of Liege)
Indeed, superparamagnetic colloids exposed to an external magnetic field form specific structures that are dependent on the features of the external field. If the magnetic field remains constant over time, superparamagnetic colloids self-organize into chains oriented in the direction of the field. If the magnetic field is rotating in the plane of the suspension, below a critical frequency, the superparamagnetic beads still aggregate into chains, and these chains rotate with the magnetic field. As the rotation speed increases, the length of these rotating chains decreases, due to the competition between magnetic and viscous effects. When the rotation reaches a certain speed, the colloids aggregate in rotating disk-like clusters.
In this presentation, we focus on the aggregation dynamics of both chains and disklike clusters, including the transition between those two states, as well as the influence of the magnetic field rotation frequency and the colloidal volume fraction. We also review the effects of this aggregation process on characteristic features of the colloidal suspension, such as the coffee-ring effect.
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700