Depletion attraction impairs the plasticity of emulsions flowing in a constriction

I. Golovkova , L. Montel , E. Wandersman , T. Bertrand , A.M. Prevost , L.L. Pontani

Bibtex , URL
Soft Matter, 16, 13
Published 07 Apr. 2020
DOI: 10.1039/c9sm02343g
ISSN: 1744-683X


We study the elasto-plastic behavior of dense attractive emulsions under a mechanical perturbation. The attraction is introduced through non-specific depletion interactions between the droplets and is controlled by changing the concentration of surfactant micelles in the continuous phase. We find that such attractive forces are not sufficient to induce any measurable modification on the scalings between the local packing fraction and the deformation of the droplets. However, when the emulsions are flowed through 2D microfluidic constrictions, we uncover a measurable effect of attraction on their elasto-plastic response. Indeed, we measure higher levels of deformation inside the constriction for attractive droplets. In addition, we show that these measurements correlate with droplet rearrangements that are spatially delayed in the constriction for higher attraction forces.

This publication is related to:

Mechanics of integrated and artificial biological systems