Experimental tests of the scaling relation for textured materials in mixtures of two immiscible fluids

Abstract

To examine the scaling relation proposed for textured materials, viscoelastic properties of binary mixtures of immiscible Newtonian fluids were measured in steady shear flows and in the transient states after step changes of the shear rate. The sample was a mixture of silicone oil and resin oil, which have almost equal density and viscosity. It was observed that (i) the shear stress and the first normal stress difference, under the steady shear flows, are almost proportional to the shear rate, and that (ii) the plots of the scaled transient stresses after a step change of shear rate, against the scaled strain, compose a single curve. These results can be well explained by the scaling relation. However, the shape of the transient stress curves after step changes of shear rate do not agree with that predicted by the constitutive equation proposed by Doi and Ohta.