Effects of confinement and external fields on structure and transport in colloidal dispersions in reduced dimensionality.

@article{Wilms2012EffectsOC,
  title={Effects of confinement and external fields on structure and transport in colloidal dispersions in reduced dimensionality.},
  author={D. Wilms and Sven Deutschl{\"a}nder and Ullrich Siems and K. Franzrahe and P. Henseler and Peter Keim and Nadine Schwierz and Peter Virnau and Kurt Binder and Georg Maret and P. Nielaba},
  journal={Journal of physics. Condensed matter : an Institute of Physics journal},
  year={2012},
  volume={24 46},
  pages={
          464119
        }
}
In this work, we focus on low-dimensional colloidal model systems, via simulation studies and also some complementary experiments, in order to elucidate the interplay between phase behavior, geometric structures and transport properties. In particular, we try to investigate the (nonlinear!) response of these very soft colloidal systems to various perturbations: uniform and uniaxial pressure, laser fields, shear due to moving boundaries and randomly quenched disorder. We study ordering phenomena… 
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8 Citations

8 Citations

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Effects of boundaries on structure formation in low-dimensional colloid model systems near the liquid-solid-transition in equilibrium and in external fields and under shear
A brief review focusing on low-dimensional colloidal model systems is given describing both simulation studies and complementary experiments, elucidating the interplay between phase behavior,…
Driven binary colloidal mixture in a 2D narrow channel with hard walls
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It is shown that the mean lane width as well as the laning order parameter increases with the channel width, and the reentrance effect is observed in the narrow channel geometry.
Effect of an external field on the structure and the phase transitions of a confined mixture of neutral and dipolar hard spheres
We study by Monte Carlo simulation the model of a binary mixture of neutral and dipolar hard spheres confined between two widely separated planar walls and subjected to a uniform external field. The…
Introduction to colloidal dispersions in external fields
Progress in the research area of colloidal dispersions in external fields within the last years is reviewed. Colloidal dispersions play a pivotal role as model systems for phase transitions in…
Dense colloidal mixtures in an external sinusoidal potential.
TLDR
The particle arrangement was investigated in dependence of the importance of particle-potential and particle-particle interactions by changing the potential amplitude and particle concentration, respectively, which results in a stronger localization and an increase in the total packing fraction favors a more homogeneous arrangement.
Clogging and transport of driven particles in asymmetric funnel arrays.
TLDR
The flow and clogging of particles driven through asymmetric funnel arrays when the commensurability ratio of the number of particles per plaquette is varied is examined to find that there can be both negative mobility where the velocity decreases with increasing driving force as well as a reentrant pinning effect.
Dynamical modes of sheared confined microscale matter.
TLDR
The dynamical transition is further reflected by the components of the stress tensor, revealing a shear-thinning behavior as well as shear stress overshoots and is discussed in the context of stochastic thermodynamics.
Concepts for soft interfaces.
TLDR
Concepts and opportunities of interfaces with soft properties are discussed, and the interface tension which governs interfacial behavior become compatible with soft and fluctuating degrees of freedom at the interface.

References

SHOWING 1-10 OF 93 REFERENCES
Colloidal systems in three-dimensional microchannels: lattice control via channel width and external force.
TLDR
The structural behavior of hard spheres interacting with repulsive (screened Coulomb) interaction in narrow constrictions is investigated using Brownian dynamics simulations and the influence of a self-organized order within the system is reflected in the velocity of the particles and their diffusive behavior.
Ordering of two-dimensional crystals confined in strips of finite width.
TLDR
It is shown that the state of the system (a strip of width D ) depends very sensitively on the precise boundary conditions at the two "walls" providing the confinement, and the effect of incommensurability of the strip width D with the triangular lattice structure is discussed.
Pattern formation in driven colloidal mixtures: tilted driving forces and re-entrant crystal freezing
The influence of an external field acting differently on the two constituents of a binary colloidal mixture performing Brownian dynamics is investigated by computer simulations and a simple theory.…
Langevin dynamics simulations of a two-dimensional colloidal crystal under confinement and shear.
TLDR
In Langevin dynamics simulations, configurations where the incommensurability of the crystalline structure is compensated by the creation of holes become relevant at high shear rates.
Lack of long-range order in confined two-dimensional model colloidal crystals.
TLDR
It is found that at densities typical of the bulk 2D triangular solid the order in the D1D strip is determined by the nature of the boundaries, and for a uniformly repulsive smooth boundary potential ordering normal to the walls is enhanced, but destroyed parallel to the wall.
Soft colloids driven and sheared by traveling wave fields.
We study the dynamics of soft colloids interacting via a Gaussian pair potential in an external moving potential which is periodic in the spatial coordinate of the direction of motion. Both dynamical…
Laser-induced reentrant freezing in two-dimensional attractive colloidal systems.
The effects of an externally applied one-dimensional periodic potential on the freezing and melting behavior of two-dimensional systems of colloidal particles with a short-range attractive…
Controlled structuring of binary hard-disk mixtures via a periodic, external potential.
TLDR
The simulations show that slight deviations in the concentration of large particles x_{A} or the diameter ratio sigma_{B}/sigma_A} have no impact on the occurrence of the various field-induced phenomena as long as the mixture stays in the relevant regime of the packing fraction eta.
Pinning and depinning of a classic quasi-one-dimensional Wigner crystal in the presence of a constriction
We studied the dynamics of a quasi-one-dimensional chain-like system of charged particles at low temperature, interacting through a screened Coulomb potential in the presence of a local constriction.…
Phase transitions of hard disks in external periodic potentials: a Monte Carlo study.
TLDR
These simulations show that the system of hard disks behaves in a fashion similar to charge-stabilized colloids that are known to undergo an initial freezing, followed by a remelting transition as the amplitude of the imposed, modulating field produced by crossed laser beams is steadily increased.
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