DISPERSIONS OF RODLIKE PARTICLES IN SHEAR-FLOW BY BROWNIAN DYNAMICS SIMULATIONS

A model 3D colloidal fluid of moderately nonspherical axisymmetric mol ecules interacting through a two-site Yukawa potential has been studie d in planar Couette flow by the Brownian dynamics simulation method. I t is shown that these fluids exhibit nonlinear rheological behavior. S hear thinning, normal stress effects and shear-induced alignment are r eported and analyzed. The influence of the one-particle diffusion tens or on the rheological and orientational properties is discussed. The s hear viscosities are lower for rods that diffuse with an anisotropic d iffusion tensor. (C) 1998 American Institute of Physics. [S0021-9606(9 8)50925-7].