Influence of hydrodynamics on many-particle diffusion in 2D colloidal suspensions.
We study many-particle diffusion in 2D colloidal suspensions with full hydrodynamic interactions through a novel mesoscopic simulation technique. We focus on the behaviour of the effective scaled tracer and collective-diffusion coefficients DT(rho)/D0 and DC(rho)/D0 respectively, where D0 is the single-particle diffusion coefficient, as a function of the density of the colloids rho. At low Schmidt numbers Sc - 1, we find that hydrodynamics has essentially no effect on the behaviour of DT (rho)/D0. At larger Sc, DT (rho)/D0 seems to be enhanced at all densities, although the differences compared to the case without hydrodynamics are rather minor. The collective-diffusion coefficient, on the other hand, is much more strongly coupled to hydrodynamical conservation laws and is distinctly different from the purely dissipative case without hydrodynamic interactions.
Falck
E
E
Laboratory of Physics - Helsinki University of Technology, FIN-02015 HUT, Finland. efalck@cc.hut.fi
Lahtinen
J M
JM
Vattulainen
I
I
Ala-Nissila
T
T
D003102:Colloids / Q000737:chemistry; D045424:Complex Mixtures / Q000737:chemistry*; D003198:Computer Simulation; D004058:Diffusion; D046911:Macromolecular Substances; D044085:Microfluidics / Q000379:methods*; D008956:Models, Chemical; D015233:Models, Statistical; D009038:Motion; D013535:Suspensions / Q000737:chemistry*
D003102:Colloids; D045424:Complex Mixtures; D046911:Macromolecular Substances; D013535:Suspensions