Dynamic Self-Assembly of Magnetic/Polymer Composites in Rotating Frames of Reference

Abstract

Small ferromagnetic particles suspended in a rotating viscous polymer and subjected to an external static magnetic field dynamically self-assemble into open-lattice, periodic structures. Depending on the orientation of the magnetic field with respect to the system's axis of rotation, these structures range from arrays of parallel plates to single, double, triple, or even quaternary helices. Dynamic self-assembly in this rotating frame of reference can be explained by an interplay between magnetic, dipole-dipole, viscous drag, and centripetal forces. Once formed, the dynamic aggregates can be made permanent by thermally curing the polymer matrix.