Flow Birefringence

Photoelastic modulators have been used to study the properties of viscous fluids, especially molten polymers in which flow birefringence has been induced by shear stress. These techniques were developed in the laboratory of Dr. Gerald Fuller at Stanford University.

The heart of the experimental setup is a special flow cell which subjects a layer of the viscous fluid to time-dependent shear stresses and creates flow birefringence. A laser beam, modulated by a photoelastic modulator, passes through the fluid at right angles to the shear stresses. The laser beam is then analyzed to determine flow birefringence and/or linear dichroism characteristics of the sheared fluid.

ADDITIONAL TOOLS

Rheology Complete Solution Packages

FURTHER READING

Gerald G. Fuller, “Optical Rheometry of Complex Fluids”, Oxford University Press, New York, 1995.

S.J. Johnson, P.L. Frattini and G.G. Fuller, “Simultaneous Dichroism and Birefringence Measurements of Dilute Colloidal Suspensions in Transient Shear Flow”, J. Coll. Interfac. Sci. 104 (2) (1985) 440-45.

S.J. Johnson and G.G. Fuller, “The Optical Anisotropy of Sheared Hematite Suspensions”, J. of Coll. And Interfac. Sci., 124 (1988) 441-451.

Contact us for more information about flow birefringence.