Structure and diffusion of active-passive binary mixtures in a single-file

Abstract

We numerically study structure and dynamics of single files composed of active particles, as well as, active-passive binary mixtures. Our simulation results show that when the persistent length of self-propelled particles is much larger than the average inter-particle separation and the self-propulsion velocity is larger than the thermal velocity, particles in the file exist as clusters of various sizes. Average cluster size and structures of the file are very sensitive to self-propulsion properties, thermal fluctuations and composition of the mixture. In addition to the variation of file composition, our study considers two sorts of mixture configurations. One corresponds to the uniform distribution of active passive throughout the mixture in the single file. In the other configuration, active particles are on one side of the file. For the both configurations, even a little fraction of active particles produces a large impact on the structure and dynamics of the file.

Graphical abstract

When persistent length of active species is much larger than average inter-particle separation, active-species in a single-file exist as clusters of various sizes. Due to the motility transfer mechanism, little fractions of active  particles have great impacts on the structure and dynamics of single-files composed of active-passive binary mixtures.