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Phase behaviour of active Brownian particles: the role of dimensionality

Stenhammar, Joakim LU ; Marenduzzo, Davide; Allen, Rosalind J. and Cates, Michael E. (2014) In Soft Matter 10(10). p.1489-1499
Abstract
Recently, there has been much interest in activity-induced phase separations in concentrated suspensions of “active Brownian particles” (ABPs), self-propelled spherical particles whose direction of motion relaxes through thermal rotational diffusion. To date, almost all these studies have been restricted to 2 dimensions. In this work we study activity-induced phase separation in 3D and compare the results with previous and new 2D simulations. To this end, we performed state-of-the-art Brownian dynamics simulations of up to 40 million ABPs – such very large system sizes are unavoidable to evade finite size effects in 3D. Our results confirm the picture established for 2D systems in which an activity-induced phase separation occurs, with... (More)
Recently, there has been much interest in activity-induced phase separations in concentrated suspensions of “active Brownian particles” (ABPs), self-propelled spherical particles whose direction of motion relaxes through thermal rotational diffusion. To date, almost all these studies have been restricted to 2 dimensions. In this work we study activity-induced phase separation in 3D and compare the results with previous and new 2D simulations. To this end, we performed state-of-the-art Brownian dynamics simulations of up to 40 million ABPs – such very large system sizes are unavoidable to evade finite size effects in 3D. Our results confirm the picture established for 2D systems in which an activity-induced phase separation occurs, with strong analogies to equilibrium gas–liquid spinodal decomposition, in spite of the purely non-equilibrium nature of the driving force behind the phase separation. However, we also find important differences between the 2D and 3D cases. Firstly, the shape and position of the phase boundaries is markedly different for the two cases. Secondly, for the 3D coarsening kinetics we find that the domain size grows in time according to the classical diffusive t1/3 law, in contrast to the nonstandard subdiffusive exponent observed in 2D. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Soft Matter
volume
10
issue
10
pages
1489 - 1499
publisher
Royal Society of Chemistry
external identifiers
  • wos:000332461800006
  • scopus:84894157050
ISSN
1744-6848
DOI
10.1039/C3SM52813H
language
English
LU publication?
yes
id
8634223b-2778-4393-982a-abb925ed4e32 (old id 4317175)
alternative location
http://pubs.rsc.org/en/content/articlelanding/2014/sm/c3sm52813h
date added to LUP
2014-02-28 12:05:35
date last changed
2017-10-22 04:17:10
@article{8634223b-2778-4393-982a-abb925ed4e32,
  abstract     = {Recently, there has been much interest in activity-induced phase separations in concentrated suspensions of “active Brownian particles” (ABPs), self-propelled spherical particles whose direction of motion relaxes through thermal rotational diffusion. To date, almost all these studies have been restricted to 2 dimensions. In this work we study activity-induced phase separation in 3D and compare the results with previous and new 2D simulations. To this end, we performed state-of-the-art Brownian dynamics simulations of up to 40 million ABPs – such very large system sizes are unavoidable to evade finite size effects in 3D. Our results confirm the picture established for 2D systems in which an activity-induced phase separation occurs, with strong analogies to equilibrium gas–liquid spinodal decomposition, in spite of the purely non-equilibrium nature of the driving force behind the phase separation. However, we also find important differences between the 2D and 3D cases. Firstly, the shape and position of the phase boundaries is markedly different for the two cases. Secondly, for the 3D coarsening kinetics we find that the domain size grows in time according to the classical diffusive t1/3 law, in contrast to the nonstandard subdiffusive exponent observed in 2D.},
  author       = {Stenhammar, Joakim and Marenduzzo, Davide and Allen, Rosalind J. and Cates, Michael E.},
  issn         = {1744-6848},
  language     = {eng},
  number       = {10},
  pages        = {1489--1499},
  publisher    = {Royal Society of Chemistry},
  series       = {Soft Matter},
  title        = {Phase behaviour of active Brownian particles: the role of dimensionality},
  url          = {http://dx.doi.org/10.1039/C3SM52813H},
  volume       = {10},
  year         = {2014},
}