Non-Newtonian viscosity in steady-state shear flows

► Viscosity of elastic fluids is described by the general law of relaxation evolution. ► Viscosity of multi-component fluids depends on stress dependent structure evolution. ► Thixotropy determines the yielding behavior of soft matters. ► Flow of multi-component colloid liquids can be stratified and strongly inhomogeneous. ► Time dependent effects and inhomogeneity lead to artifacts in viscosity measurements.