Published online by Cambridge University Press: 15 February 2011
When an electric field is applied to a colloidal suspension of micronsize particles, the particles are attracted to each other in the direction of the external field. They line up to form chains and columns across the gap of the electrodes and therefore drastically change the rheological properties of the suspension. These electrorheological phenomena have been studied extensively by recent computer simulation work [1,2], and it is generally accepted that the interactions between the induced electric dipole moments of the particles are responsible for their alignment in the external fields. To avoid net migrations of particles in electric fields of small inhomogeneity, alternating fields are generally used in experiments.