Diffusiophoretic manipulation of particles in a drop deposited on a hydrogel. Author François Boulogne, Sangwoo Shin, Julien Dervaux, Laurent Limat, Howard Stone 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 DOI 10.1039/c7sm00915a Alternate Journal Soft Matter PMID 28650031 PubMedGoogle ScholarBibTeXEndNote X3 XML