Lattice-Boltzmann simulation of the sedimentation of charged disks.
We report a series of lattice-Boltzmann simulations of the sedimentation velocity of charged disks. In these simulations, we explicitly account for the hydrodynamic and electrostatic forces on disks and on their electrical double layer. By comparing our results with those for spheres with equal surface and charge, we can clarify the effect of the particle shape on the sedimentation process. We find that disks and spheres exhibit a different dependence of the sedimentation velocity on the Debye screening length. An analysis of the behavior of highly charged disks (beyond the scope of the linearized Poisson-Boltzmann equation) shows that, in that regime, the charge dependence of the sedimentation velocity of disks and spheres is similar. This suggests that, at high charge, the effective hydrodynamic shape of the disks becomes more spherical.
Capuani
Fabrizio
F
FOM Institute for Atomic and Molecular Physics (AMOLF), Kruislaan 407, 1098 SJ Amsterdam, The Netherlands.
Pagonabarraga
Ignacio
I
Frenkel
Daan
D
D016880:Anisotropy; D002627:Chemistry, Physical / Q000379:methods*; D003198:Computer Simulation; D004563:Electrochemistry / Q000379:methods; D017276:Friction; D007700:Kinetics; D008956:Models, Chemical; D008962:Models, Theoretical; D008968:Molecular Conformation; D055672:Static Electricity; D013499:Surface Properties