Magnetophoresis of particles and aggregates in concentrated magnetic fluids.

Experimental and theoretical studies were carried out to investigate the problem of magnetophoresis in a thin layer of concentrated magnetic fluids, concerning the aspect of particle aggregation. A heuristic theoretical model, describing diffusion fluxes of individual and aggregated particles, is suggested. The solution of related diffusion and magnetostatic problems are compared with the experimental data. The analysis of the data shows that the aggregates essentially change the concentration profile. Good agreement between experimental and theoretical curves is observed in the case when the aggregates contain, on average, more than ten particles.