Magnetoviscosity of Micronic Suspensions

Abstract

Rheological measurements are carried out on aqueous magnetic suspensions (10% ⩽ Φv ⩽ 30%) submitted to a low magnetic field. The suspended particles are micronic latex spheres made of very small ((10 ÷ 100) Å) grains of iron oxyde embedded in a polystyrene matrix. The suspension exhibit a strong increase of the apparent viscosity which is measured by capillary flow experiments. The rheological behaviour is interpreted on the basis of a Bingham model with a yield stress due to the fibrinated structure induced by the magnetic field.