(474e) Brownian Dynamic Simulation of Soft Magnetic Ellipsoidal Mesoparticle Suspensions

Suspensions of sub-micron magnetic mesoparticles composed of soft magnetic materials are recently being considered for various applications, such as in cancer treatment. In these suspensions the static and dynamic behavior of the particles depends on both the magnitude of the applied magnetic field and the relative orientation of the particles with the applied magnetic field, in addition to hydrodynamic and thermal effects. Here, the rotational motion of magnetically-soft tri-axial ellipsoidal particles suspended in a Newtonian fluid was studied using rotational Brownian dynamics simulations. The approach considers the stochastic angular momentum equation (Langevin equation) in an orientation space described by quaternion parameters. The algorithm quantifies the magnetization of a monodisperse particle suspension in dilute limit conditions under applied steady and time-varying magnetic fields. The algorithm also takes into account the field-dependent relative permeability of the particle’s bulk material. We have considered the equilibrium magnetization at different dimensionless field amplitudes and dynamic susceptibility in response to an oscillating magnetic field at different dimensionless frequencies for ellipsoidal mesoparticle suspensions with different geometric aspect ratios and different particle sizes.