Issue 12, 2012

Out-of-equilibrium forces between colloids

Abstract

Two colloidal probe particles are held with optical traps orthogonal to a uniformly flowing suspension of colloidal bath particles. Using confocal microscopy, the local bath suspension microstructure is characterized as a function of the probe separation and flow velocity. At sufficiently close separations, bath particles are excluded from passing between the probes, resulting in an asymmetric, non-equilibrium microstructure in which the major features are a depleted region between the probes and dense boundary layers along the surfaces that face away from the neighboring probe. As a consequence, the drag force acting on the probes is lower than that acting on a single probe and a net force pushes the probes together along their line of centers. The strength of the latter mutual force increases with increasing flow velocity. These experiments demonstrate that depletion-like forces can be induced between two particles by a non-equilibrium microstructure in a strongly driven suspension.

Graphical abstract: Out-of-equilibrium forces between colloids

Article information

Article type
Paper
Submitted
19 Sept. 2011
Accepted
13 Janv. 2012
First published
14 Febr. 2012

Soft Matter, 2012,8, 3335-3341

Out-of-equilibrium forces between colloids

I. Sriram and E. M. Furst, Soft Matter, 2012, 8, 3335 DOI: 10.1039/C2SM06784F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements