RHEOLOGICAL STUDY OF MAGNETIC PARTICLE SUSPENSIONS

Viscometry was used to investigate the microstructural properties of v arious magnetic particle suspensions. Our study was focused primarily on the shape (acicular versus plate-like effects) of magnetic particle s, magnetic particle and/or flee concentration, as well as the effects of shear rate. Mean field theory and the Mooney equation were adopted to estimate a maximum packing concentration of magnetic particles (ph i(infinity)) as well as the intrinsic viscosity ([eta]). The values of phi(proportional to) and [eta] for different suspensions were used to interpret the microstructure of magnetic particle suspensions. Furthe r, the Casson equation was employed to investigate the dependence of s hear rate on the viscosity.