Hostname: page-component-5db58dd55d-jhf8m Total loading time: 0 Render date: 2026-06-14T22:38:15.711Z Has data issue: false hasContentIssue false

Diffusiophoresis in narrow channel flows

Published online by Cambridge University Press:  10 September 2018

Jesse T. Ault*
Affiliation:
Biomedical Sciences, Engineering, and Computing Group, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
Sangwoo Shin
Affiliation:
Department of Mechanical Engineering, University of Hawaii at Manoa, Honolulu, HI 96822, USA
Howard A. Stone
Affiliation:
Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544, USA
*
Email address for correspondence: aultjt@ornl.gov

Abstract

Flows containing suspended colloidal particles and dissolved solutes are found in a multitude of natural and man-made systems including hydraulic fractures, water filtration systems and microfluidic devices, e.g. those designed for biological or medical applications. In these types of systems, unexpected particle dynamics such as rapid particle transport and focusing has been observed in the presence of local solute gradients due to the cooperating or competing effects of fluid advection and particle diffusiophoresis, the latter driven by local chemical gradients. We develop analytical expressions for the fluid, solute and particle dynamics in long, narrow channels due to the combined influence of pressure-driven channel flow with diffusiophoretic and diffusioosmotic effects. The results confirm a rapid particle focusing effect that can be controlled by manipulating the particle, solute and flow properties, as well as the channel’s geometry and surface chemistry. Thus, we propose a new approach for performing microfluidic zeta potentiometry, as well as techniques for sorting, concentrating and/or capturing particles based on their sizes or zeta potentials. Finally, we demonstrate that diffusioosmotic effects can be used to pump fluid against a pressure gradient.

Information

Type
JFM Papers
Copyright
© Cambridge University Press 2018. Parts of this are a work of the US Government and not subject to copyright protection in the United States. 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable