Diffusiophoretic manipulation of particles in a drop deposited on a hydrogel.

Publication Year
2017

Type

Journal Article
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.

Journal
Soft Matter
Volume
13
Issue
30
Pages
5122-5129
Date Published
2017 Aug 02
ISSN Number
1744-6848
Alternate Journal
Soft Matter
PMID
28650031