Binary Mixtures in Linear Convection Arrays

TL;DR

This paper numerically explores how mixtures of active and passive particles behave in linear convection arrays, revealing effects like stirring and separation driven by active particle motility.

Contribution

It introduces a detailed numerical analysis of active-passive particle mixtures in convection arrays, highlighting mechanisms for stirring and separation based on active particle motility.

Findings

Active particles stir passive colloids effectively.

Increasing active particle motility causes separation and clustering.

Diffusion constants depend on active mixture parameters.

Abstract

We numerically investigated the dynamics of a mixture of finite-size active and passive particles in a linear array of convection rolls. The interplay of advection and steric interactions produces a number of interesting effects, like the stirring of a passive colloidal fluid by a small fraction of slow active particles, or the separation of the mixture active and passive colloidal fractions by increasing the motility of the active one, which eventually clusters in stagnation areas along the array walls. These mechanisms are quantitatively characterized by studying the dependence of the diffusion constants of the active and passive particles on the parameters of the active mixture fraction.