Rheo-dielectric effect in liquid suspensions

A rheo-dielectric effect, dielectrostriction, relates the polarizability of a material to its deformation. Stress, strain, strain rate or some combination of these parameters could be the state variables for a given material. The description of the dielectrostriction in isotropic materials involves two material coefficients. A key advantage of the presented experimental technique is the utilization of a single deformation mode, shear deformation, for two independent measurements of the material coefficients ill liquid suspensions. The Study is conducted with micro- and nano-sized alumina oxide (Al2O3) particles dispersed either in silicone oil (Newtonian fluid) or in liquid silicone elastomer (viscoelastic fluid). The dielectrostriction response of each suspension is compared with those of the corresponding base liquids. The selection of strain or stress as the state variable of deformation is discussed. Material coefficients for both the strain- and stress-based descriptions are presented for each system.