The origin of the interparticle potential of electrorheological fluids

The particles of electrorheological fluids can be modelled a s dielectric sphere (DS) immersed in a continuum dielectric. When an external field is applied, polarization charges are induced on the surfaces of the spheres that can be represented as point dipoles placed in the centres of the spheres. When the DSs are close to each other, the induced charge distributions are distorted by the electric field of the neighbouring DSs. This is the origin of the interaction potential between the DSs. The calculation of this energy is very time consuming, therefore, the DS model cannot be used in molecular simulations. In this paper, we show that the interaction between the point dipoles approximates the interaction of DSs appropriately. The polarizable point dipole model provides better results, but this model is not pair-wise additive, so it is not so practical in particle simulations