Getting out of a tight spot: Cooperative unclogging of hydrogel particles in disordered porous media

TL;DR

This study uses pore network modeling to understand how hydrogel particles move and clog in porous media, revealing a new cooperative effect where more particles enable deeper penetration due to fluid redirection.

Contribution

Introduces a dimensionless squeezing parameter and uncovers cooperative particle behavior, linking microscopic mechanics to macroscopic transport in porous media.

Findings

A squeezing parameter predicts particle penetration depth.

Adding more particles enhances penetration through cooperative effects.

Fluid redirection causes particles to overcome tight pores.

Abstract

We use event-driven pore network modeling to study the transport of hydrogel particles through disordered porous media -- a process that underlies diverse applications. By simulating particle advection, deformation, and clogging at the pore scale, we identify a dimensionless "squeezing parameter" that quantitatively predicts the depth to which particles penetrate into a given medium across diverse conditions. Our simulations also uncover a surprising cooperative effect: adding more particles enables them to penetrate deeper into the medium. This phenomenon arises because individual particles redirect fluid to adjacent throats, forcing nearby particles through tight pores that they would otherwise clog. Altogether, these results help to establish a quantitative framework that connects microscopic particle mechanics to macroscopic transport behavior.