Feasibility of multi-particle collision dynamics for rod-like particles and its application to a change in the orientational regime of a hematite particle suspension

Abstract

We have verified that the method of multi-particle collision dynamics (MPCD) is able to activate a physically reasonable level of random motion in the medium of virtual fluid particles and activate the translational, ordinary rotational and spin rotational Brownian motion of the magnetic rod-like particles. MPCD was then applied to a quasi-2D system of rod-like hematite particles. The particle Brownian motion was found slightly over-activated, but this tendency decreased with smaller simulation time steps. The deviation from the theoretical value in the present results may be regarded to be acceptable as a first approximation since the Brownian motion was activated without the addition of any special technique. The applied magnetic field strength is found to play a significant role to enhance the order of the alignment of the raft-like clusters along the direction of the applied magnetic field. A similar orientational regime change along the applied magnetic field may be accomplished by an increase in the volumetric fraction of magnetic particles. We have therefore concluded that both an applied magnetic field and the particle volumetric fraction may be feasible parameters for inducing a regime change in the ordering of the orientation of rod-like hematite particles.