Microstructure formation and macroscopic dynamics of ferrofluid emulsion in rotating magnetic field

Abstract

The ferrofluid-in-water emulsion has been produced and studied. The microstructure formation in a flat layer of such emulsion under the action of in-plane rotating magnetic field has been observed. Several microstructure types have been found such as chain-like aggregates, disc-like clusters, branching and space-occupying structures. The time evolution of the formation process has been analysed. The revealed microstructures have been computationally investigated by molecular dynamics simulations. The microstructure dynamics in ferrofluid emulsions manifests itself in macroscopic mechanical effects. We analysed the appearance of macroscopic torque on a ferrofluid emulsion sample in a rotating magnetic field. The value of the torque has been measured as a function of magnetic field strength and frequency