Migration of polystyrene microparticles in aqueous media caused by electromagnetic buoyancy

A novel concept for the migration of microparticles in an electrolyte solut ion, electromagnetophoresis (EMP), was demonstrated for the first time usin g a homogeneous magnetic field applied at right angles to the current in a closed microcell. The direction of the migration of polystyrene latex parti cles was perpendicular to the magnetic field and to the current, whereas it was reverse to a hypothetical Lorentz force expected for a positive charge in the system. The experimental results showed that the larger were the pa rticles' diameters, the faster did they migrate in proportion to the second power of the diameter. Moreover, the velocity of the migration was proport ional to both the current and the magnetic field. These results proved that the dominant force of the migration was electromagnetic buoyancy.