Rotational viscometers are useful for measuring viscosity of non-Newtonian solutions, owing to their ability to apply a uniform shear rate that can be varied by a simple change in rotation speed. After a brief review of rotational rheometer geometries, we focus on the specific example of polyelectrolyte solutions. These solutions can be shear thinning at very low shear rates and concentrations, where the zero shear rate viscosity is only a few times the viscosity of the solvent.
展开▼
