R. Pesche et al., Brownian dynamics study of dynamic scaling and related freezing criteria in quasi-two-dimensional dispersions, J CHEM PHYS, 114(19), 2001, pp. 8701-8707
We present a Brownian dynamics simulation study of static and dynamic prope
rties of quasi-two-dimensional dispersions of colloidal spheres interacting
by long-range screened electrostatic and by dipolar magnetic forces, respe
ctively. The calculated van Hove real-space dynamic correlation functions,
mean squared displacements, and hydrodynamic functions are shown to obey a
dynamic scaling behavior in terms of a characteristic relaxation time relat
ed to the geometrical mean particle distance. Hydrodynamic interactions int
roduce a second characteristic length scale, and they lead to a more restri
cted scaling behavior with an enhancement of self-diffusion. As a consequen
ce of dynamic scaling, the dynamical criterion of Lowen [Phys. Rev. E 53, R
29 (1996)] for the onset of colloidal freezing is shown to be equivalent to
a two-dimensional freezing criterion related to the static structure facto
r. (C) 2001 American Institute of Physics.