Phase Behavior of Active Swimmers in Depletants: Molecular Dynamics and Integral Equation Theory

TL;DR

This study investigates how self-propelling active particles influence phase behavior in colloid-polymer mixtures, revealing that activity broadens the phase coexistence region through molecular dynamics and integral equation analysis.

Contribution

It introduces a novel combination of the Vicsek model with the Asakura-Oosawa framework to analyze active colloid-polymer mixtures, demonstrating enhanced phase separation.

Findings

Active particles promote phase separation.

The coexistence region is broadened by activity.

Results are consistent across methods.

Abstract

We study the structure and phase behavior of a binary mixture where one of the components is self-propelling in nature. The inter-particle interactions in the system were taken from the Asakura-Oosawa model, for colloid-polymer mixtures, for which the phase diagram is known. In the current model version the colloid particles were made active using the Vicsek model for self-propelling particles. The resultant active system was studied by molecular dynamics methods and integral equation theory. Both methods produce results consistent with each other and demonstrate that the Vicsek model based activity facilitates phase separation, thus broadening the coexistence region.