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Nonequilibrium dynamics of mixtures of active and passive colloidal particles

Wittkowski, Raphael; Stenhammar, Joakim LU and Cates, Michael E. (2017) In New Journal of Physics 19(10).
Abstract

We develop a mesoscopic field theory for the collective nonequilibrium dynamics of multicomponent mixtures of interacting active (i.e., motile) and passive (i.e., nonmotile) colloidal particles with isometric shape in two spatial dimensions. By a stability analysis of the field theory, we obtain equations for the spinodal that describes the onset of a motility-induced instability leading to cluster formation in such mixtures. The prediction for the spinodal is found to be in good agreement with particle-resolved computer simulations. Furthermore, we show that in active-passive mixtures the spinodal instability can be of two different types. One type is associated with a stationary bifurcation and occurs also in one-component active... (More)

We develop a mesoscopic field theory for the collective nonequilibrium dynamics of multicomponent mixtures of interacting active (i.e., motile) and passive (i.e., nonmotile) colloidal particles with isometric shape in two spatial dimensions. By a stability analysis of the field theory, we obtain equations for the spinodal that describes the onset of a motility-induced instability leading to cluster formation in such mixtures. The prediction for the spinodal is found to be in good agreement with particle-resolved computer simulations. Furthermore, we show that in active-passive mixtures the spinodal instability can be of two different types. One type is associated with a stationary bifurcation and occurs also in one-component active systems, whereas the other type is associated with a Hopf bifurcation and can occur only in active-passive mixtures. Remarkably, the Hopf bifurcation leads to moving clusters. This explains recent results from simulations of active-passive particle mixtures, where moving clusters and interfaces that are not seen in the corresponding one-component systems have been observed.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
active colloidal particles, active-passive mixtures, mesoscopic field theory particle-resolved simulations, motility-induced instability
in
New Journal of Physics
volume
19
issue
10
publisher
IOP Publishing Ltd.
external identifiers
  • scopus:85032800474
  • wos:000412283200001
ISSN
1367-2630
DOI
10.1088/1367-2630/aa8195
language
English
LU publication?
yes
id
2f4ae211-5acb-4669-bc2c-74971250f919
date added to LUP
2017-11-15 08:26:19
date last changed
2018-06-24 05:18:27
@article{2f4ae211-5acb-4669-bc2c-74971250f919,
  abstract     = {<p>We develop a mesoscopic field theory for the collective nonequilibrium dynamics of multicomponent mixtures of interacting active (i.e., motile) and passive (i.e., nonmotile) colloidal particles with isometric shape in two spatial dimensions. By a stability analysis of the field theory, we obtain equations for the spinodal that describes the onset of a motility-induced instability leading to cluster formation in such mixtures. The prediction for the spinodal is found to be in good agreement with particle-resolved computer simulations. Furthermore, we show that in active-passive mixtures the spinodal instability can be of two different types. One type is associated with a stationary bifurcation and occurs also in one-component active systems, whereas the other type is associated with a Hopf bifurcation and can occur only in active-passive mixtures. Remarkably, the Hopf bifurcation leads to moving clusters. This explains recent results from simulations of active-passive particle mixtures, where moving clusters and interfaces that are not seen in the corresponding one-component systems have been observed.</p>},
  articleno    = {105003},
  author       = {Wittkowski, Raphael and Stenhammar, Joakim and Cates, Michael E.},
  issn         = {1367-2630},
  keyword      = {active colloidal particles,active-passive mixtures,mesoscopic field theory particle-resolved simulations,motility-induced instability},
  language     = {eng},
  month        = {10},
  number       = {10},
  publisher    = {IOP Publishing Ltd.},
  series       = {New Journal of Physics},
  title        = {Nonequilibrium dynamics of mixtures of active and passive colloidal particles},
  url          = {http://dx.doi.org/10.1088/1367-2630/aa8195},
  volume       = {19},
  year         = {2017},
}