Journal Article

FZJ-2021-01848

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Motility-Induced Inter-Particle Correlations and Dynamics: a Microscopic Approach for Active Brownian Particles

Dhont, J. K. G. (Corresponding author)FZJ* ; Briels, W.FZJ* ; Park, G. W.FZJ*

2021
Royal Soc. of Chemistry London

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Please use a persistent id in citations: http://hdl.handle.net/2128/27941  doi:10.1039/D1SM00426C

Abstract: Amongst the theoretical approaches towards dynamics and phase behaviour of suspensions of active Brownian particles (ABPs), no attempt has been made to specify motility induced inter-particle correlations as quantified by the pair-correlation function. Here we derive expressions for the pair-correlation function for ABPs with very short-ranged direct interactions for small and large swimming velocities and low concentrations. The pair-correlation function is the solution of a differential equation that is obtained from the Fokker-Planck equation for the probability density function of the positions and orientations of the ABPs. For large swimming Peclet numbers lambda, the pair-correlation function is highly asymmetric. The pair-correlation function attains a large value ~lambda within a small region of spatial extent ~1/lambda near contact of the ABPs when the ABPs approach each other. The pair-correlation function is small within a large region of spatial extent ~lambda^1/3 when the ABPs move apart, with a contact value that is essentially zero. From the explicit expressions for the pair-correlation function, Fick's diffusion equation is generalized to include motility. It is shown that mass transport, in case of large swimming velocities, is dominated by a preferred swimming direction that is induced by concentration gradients. The expression for the pair-correlation function derived in this paper could serve as a starting point to obtain approximate results for high concentrations, which could then be employed in a first-principle analysis of the dynamics and phase behaviour of ABPs at higher concentrations.

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Contributing Institute(s):

1. Biomakromolekulare Systeme und Prozesse (IBI-4)

Research Program(s):

1. 524 - Molecular and Cellular Information Processing (POF4-524) (POF4-524)

Appears in the scientific report 2021

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Database coverage:
; ; ; Allianz-Lizenz / DFG ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Essential Science Indicators ; IF < 5 ; JCR ; National-Konsortium ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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