Diffusion and magnetotransport in ferrofluids containing chain-shaped aggregates

Abstract

Abstract-The effect of chain structures on particle diffusion in nanodisperse ferrofluids subjected to exter nal magnetic fields is studied. It is shown that the chain formation imparts very strong anisotropy to the dif fusion properties of ferrofluids: the diffusion coefficient along a field appears to be approximately two orders of magnitude higher than that in the transverse direction. The presence of the chains changes the particle magnetophoresis coefficient significantly.

How nonmagnetic particles intensify rotational diffusion in magnetorheological fluids

“…Typical fields where diffusion plays a crucial role are self-assembly and rheology/micro-rheology of complex fluids (polymer solutions, suspensions of rod-like particles or granular gases) [2][3][4][5][6]. A special kind of particulate suspensions for which diffusion has also been studied are field-driven colloids, suspensions of polarizable particles dispersed in a liquid carrier which undergo changes of their mechanical properties in the presence of external fields [7][8][9][10][11][12]. Examples of these smart materials are ferrofluids or electrorheological and magnetorheological (MR) fluids.…”

Magnetophoretic Equilibrium of a Polydisperse Ferrofluid

“…At high λ aggregation takes place in a broad concentration range, including extremely low values of Φ [32]. In turn, the effect of aggregates on the mass-transfer properties of ferrofluids is known to be significant and mathematically cumbersome to account [33]. Luckily, high dipolar coupling constants are not typical for industrial ferrofluids [28].…”