Single-wire HGMS of colloidal particles: the evolution of concentration profiles

The authors present and discuss the initial evolution on short time scales of the concentration profile of colloidal Mn/sub 2/O/sub 3/ particles around a magnetized steel wire, in the regions of repulsive interaction. When an external magnetic field is applied to a colloid that surrounds a magnetizable filter element, the initially homogeneous density will evolve towards a new equilibrium distribution. In the region of repulsive magnetic particle-wire interaction, this evolution leads to the distinct phenomenon of a rather sharp boundary that moves outward to larger distances. Observation of the shape and propagation velocity of this boundary provides means to check and refine the theoretical models. >