title: Model of dynamic self-assembly in ferromagnetic suspensions at liquid interfaces.
abstract: Ferromagnetic microparticles suspended at the interface between immiscible liquids and energized by an external alternating magnetic field show a rich variety of self-assembled structures, from linear snakes to radial asters. In order to obtain insight into the fundamental physical mechanisms and the overall balance of forces governing self-assembly, we develop a modeling approach based on analytical solutions of the time-averaged Navier-Stokes equations. These analytical expressions for the self-consistent hydrodynamic flows are then employed to modify effective interactions between the particles, which in turn are formulated in terms of the time-averaged quantities. Our method allows effective computational verification of the mechanisms of self-assembly and leads to a testable prediction, e.g., on the transitions between various patterns versus viscosity of the solvent.
authors.affiliation: Department of Engineering Science and Applied Mathematics, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA and Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Piet
authors.forename: A V
authors.initials: AV
authors.lastname: Straube
authors.forename: A
authors.initials: A
authors.lastname: Snezhko
authors.forename: I S
authors.initials: IS
authors.lastname: Aranson