Flow Birefringence of Semdilute Polymer Solutions

Shear-induced orientation of viscoelastic materials usually leads to an anisotropy of the refractive index of the sample. For a polymeric solution, the extent of orientation depends on its nature —chain rigidity, presence of charges for polyelectrolytes— and on its structure —entanglements, conformation etc. Flow birefringence then reveals a suitable technique to study these phenomena.