LATTICE MODELS OF GROWTH OF ALIGNED DIPOLAR FLUIDS

The aggregation kinetics of a lattice model of aligned dipoles is exam ined as a simple model for electrorheological or magnetorheological fl uids. We have found that the mechanism of cluster growth depends on ti me. Initial growth of clusters is dominated by monomer field-induced m igration, but subsequent growth of the clusters at later stages is str ongly dependent on monomer depletion and anisotropic diffusion of the aligned clusters. We find that the mean size of the chain [s(t)] growt h with time, t, according to [s(t)] similar to t(z) with the exponent decreasing with increasing volume fraction, in accordance with recent experiments. This generic growth law is rather insensitive to the grow th procedure of the model.