|Title||Diffusiophoretic manipulation of particles in a drop deposited on a hydrogel.|
|Publication Type||Journal Article|
|Year of Publication||2017|
|Authors||Boulogne, F, Shin, S, Dervaux, J, Limat, L, Stone, HA|
|Date Published||2017 Jun 26|
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.
|Alternate Journal||Soft Matter|