Rod-assisted heterogeneous nucleation in active suspensions.
Yunfei Du1, Huijun Jiang, Zhonghuai Hou
1Hefei National Laboratory for Physical Sciences at Microscales and Department of Chemical Physics, iChEM, University of Science and Technology of China, Hefei, Anhui 230026, China. hzhlj@ustc.edu.cn.
Soft Matter
|June 27, 2020
Summary
Introducing a passive seed into active Brownian particles dramatically speeds up phase separation. This heterogeneous nucleation accelerates the process, leading to distinct phase behaviors not seen in homogeneous systems.
Area of Science:
- Physics of active matter
- Soft condensed matter physics
- Statistical mechanics
Background:
- Recent interest in motility-induced phase separation (MIPS) and nucleation in active particle systems.
- Limited research on heterogeneous nucleation in active systems compared to passive systems.
- Previous studies often focused on homogeneous active particle suspensions.
Purpose of the Study:
- To investigate heterogeneous nucleation and phase behavior in active Brownian particle suspensions.
- To explore the effect of a rod-like passive seed on nucleation and phase separation.
- To understand the role of activity in driving novel phase behaviors.
Main Methods:
- Simulating a suspension of active Brownian particles with a rod-like passive seed.
- Analyzing nucleation rates and phase separation dynamics.
- Observing the interaction between the seed and the forming dense phase.
- Investigating re-entrant phase behavior as a function of particle activity.
Main Results:
- A passive seed exponentially accelerates nucleation rate, inducing rapid phase separation in dilute active systems.
- The seed detaches from the dense phase post-separation, unlike an impurity.
- Re-entrant phase behavior observed: single-phase states at low and high activities, phase separation in between.
- Heterogeneous nucleation in active systems exhibits unique behaviors compared to passive systems.
Conclusions:
- Heterogeneous nucleation provides a powerful route to control phase separation in active matter.
- The observed re-entrant phase behavior and seed detachment highlight novel physics in active systems.
- This study opens avenues for exploring complex phase dynamics driven by external seeds in active matter.
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