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arXiv · 1305.4185

Dynamical clustering and phase separation in suspensions of self-propelled colloidal particles

Ivo Buttinoni·Julian Bialké·Felix Kümmel·Hartmut Löwen·Clemens Bechinger·Thomas Speck
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Abstract

We study experimentally and numerically a (quasi) two dimensional colloidal suspension of self-propelled spherical particles. The particles are carbon-coated Janus particles, which are propelled due to diffusiophoresis in a near-critical water-lutidine mixture. At low densities, we find that the driving stabilizes small clusters. At higher densities, the suspension undergoes a phase separation into large clusters and a dilute gas phase. The same qualitative behavior is observed in simulations of a minimal model for repulsive self-propelled particles lacking any alignment interactions. The observed behavior is rationalized in terms of a dynamical instability due to the self-trapping of self-propelled particles.

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Ivo Buttinoni, Julian Bialké, Felix Kümmel, Hartmut Löwen, Clemens Bechinger, Thomas Speck. 2013-05-17. Dynamical clustering and phase separation in suspensions of self-propelled colloidal particles. https://doi.org/10.1103/physrevlett.110.238301

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