Colloid Aggregation under Confined Flow

Colloidal suspensions are ubiquitous in many natural (geophysical fluids, blood…) and industrial (muds, concrete…) processes. When a suspension is confined, colloidal interactions may prevail over the hydrodynamic drag, thus leading to the formation of aggregates through a jamming-like transition. Using microfluidic tools, we investigate at the pore scale the flow-driven aggregation of colloids on solid structures.

The accumulation of particles within constrictions is a route towards clogging. This process can be understood through a two-step scenario, distinguishing the particle deposition over the pore walls or over colloids themselves. The subsequent accumulation of particles over porous or non-porous surfaces exhibits a rich phenomenology. Both the obtained shape patterns and the very nature of the aggregate (cohesive or labile) indeed result from the interplay between colloidal interactions and
hydrodynamic drag during its formation.