Theory of the low-frequency electrorotation of polystyrene particles in electrolyte solution

An interpretation is given for the cofield rotation observed in low-frequency electrorotation experiments using polystyrene particles in electrolyte solution. It is shown that the main cause of the particle rotation is the electroosmotic velocity of the electrolyte inside the thin double layer, rather than the torque exerted by the rotating electric field on the out of phase part of the induced dipole moment.