Diffusiophoretic manipulation of particles in a drop deposited on a hydrogel. Issue 30 (26th June 2017)

• Record Type: Journal Article
• Authors: Boulogne, François; Shin, Sangwoo; Dervaux, Julien; Limat, Laurent; Stone, Howard A.
• Is Part Of: Soft matter. Volume 13:Issue 30(2017)
• Page Start: 5122
• Page End: 5129
• Publication Date: 2017-06-26
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/c7sm00915a
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : Effect of salt concentration C s on the deposition of particles on hydrogels. Abstract : We report an experimental study on the manipulation of colloidal particles in a drop sitting on a hydrogel. The manipulation is achieved by diffusiophoresis, which describes a directed motion of particles induced by solute gradients. By letting the solute concentrations for the drop and the hydrogel be different, we control the motion of particles in a stable suspension, which is otherwise difficult to achieve. We show that diffusiophoresis can cause the particles to move either toward or away from the liquid–air interface depending on the direction of the solute gradient and the surface charge of the particles. We measure the particle adsorption experimentally and rationalize the results with a one-dimensional numerical model. We show that diffusiophoretic motion is significant at the lengthscale of a drop deposited on a hydrogel, which suggests a simple method for the deposition of particles on hydrogels.