Volume 24, Issue 1 e202200471
Research Article

Binary Mixtures in Linear Convection Arrays

Pulak K. Ghosh

Corresponding Author

Pulak K. Ghosh

Department of Chemistry, Presidency University, Kolkata, 700073 India

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Yuxin Zhou

Yuxin Zhou

Center for Phononics and Thermal Energy Science, Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai, 200092 China

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Yunyun Li

Yunyun Li

Center for Phononics and Thermal Energy Science, Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai, 200092 China

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Fabio Marchesoni

Corresponding Author

Fabio Marchesoni

Center for Phononics and Thermal Energy Science, Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai, 200092 China

Dipartimento di Fisica, Università di Camerino, I-62032 Camerino

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Franco Nori

Franco Nori

Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama, 351-0198 Japan.

Physics Department, University of Michigan, Ann Arbor, Michigan, 48109-1040 USA.

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First published: 20 September 2022

Graphical Abstract

Binary mixtures of active-passive particles in convection arrays exhibit a conspicuous phase separation into two distinct colloidal fluids for strong self-propulsion of the active fraction. The passive fluid circulating inside the convection rolls and the active one accumulating in stagnation areas along the array walls. On the other hand, a little fraction of weak active particles exert a strong stirring action on a passive colloidal fluid.

Abstract

We numerically investigated the dynamics of a mixture of finite-size active and passive disks in a linear array of two-dimensional 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.

Conflict of interest

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.