Depletion potentials in colloidal mixtures of spheres and rods

@article{Roth2003DepletionPI,
  title={Depletion potentials in colloidal mixtures of spheres and rods},
  author={Roland Roth},
  journal={Journal of Physics: Condensed Matter},
  year={2003},
  volume={15}
}
  • R. Roth
  • Published 15 January 2003
  • Physics
  • Journal of Physics: Condensed Matter
We calculate the depletion potential between two hard spheres of radii Rs and that between one hard sphere and a planar hard wall in a sea of hard rigid spherocylindrical rods of length L and radius Rr. Unlike earlier studies our approach takes into account the true geometry of the problem and gives, to first order in the rod density, the exact depletion potential for all values of Rs, L, and Rr. 

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References

SHOWING 1-10 OF 18 REFERENCES
Depletion forces between two spheres in a rod solution
We study the depletion interaction between spherical particles of radius R immersed in a dilute solution of rigid rods of length L. The computed interaction potential is, within numerical accuracy,
Density functional theory for colloidal rod-sphere mixtures.
  • M. Schmidt
  • Physics
    Physical review. E, Statistical, nonlinear, and soft matter physics
  • 2001
TLDR
A density functional theory is presented for a model colloidal mixture of hard spheres and infinitely thin hard rods to obtain a functional that features the correct dimensional crossover and the exact low density limit.
Depletion potential in hard-sphere fluids
A versatile new approach for calculating the depletion potential in a hard-sphere mixture is presented. This is valid for any number of components and for arbitrary densities. We describe two
Phase behavior of colloidal rod-sphere mixtures
We investigate the depletion induced phase separation in mixed suspensions of colloidal spheres with diameter s and colloidal rods with length L and diameter D. Using an extension of the free
Theory of the depletion force due to rodlike polymers
The entropic depletion force, in colloids, arises when large particles are placed in a solution of smaller ones, and sterically constrained to avoid them. In this paper, we consider a system of two
Numerical study of the phase diagram of a mixture of spherical and rodlike colloids
Fluid–fluid phase separation in a simple model for a colloid dispersed in a solution of stiff rodlike polymers is studied by means of Gibbs ensemble Monte Carlo simulations. The fluid–solid
Depletion potential in hard-sphere mixtures: theory and applications
  • Roth, Evans, Dietrich
  • Physics
    Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics
  • 2000
TLDR
An accurate parametrization of the depletion potential in hard-sphere fluids, which should be useful for effective Hamiltonian studies of phase behavior and colloid structure.
Phase transitions, aggregation and crystallization in mixed suspensions of colloidal spheres and rods
We have studied the coupling of aggregation and crystallization in a mixture of colloidal spheres and colloidal rods. Taking advantage of specially prepared fluorescent silica spheres we are able to
Direct simulation of the phase behavior of binary hard-sphere mixtures: test of the depletion potential description
We study the phase behavior of additive binary hard-sphere mixtures by direct computer simulation, using a new technique which exploits an analog of the Gibbs adsorption equation. The resulting phase
Entropic torque.
Quantitative predictions are presented of a depletion-induced torque and force acting on a single colloidal hard rod immersed in a solvent of hard spheres close to a planar hard wall. This torque and
...
1
2
...