Orientation Birefringence of Macromolecular Solutions in Shear Flow and Electric Field

摘要

The orientation distribution function of polar rigid macromolecules in dielectric media is obtained by solving the rotary diffusion equation in the steady state, when the solution flows with a constant velocity gradient and is acted upon by an electrostatic field perpendicular to the stream line. The optical properties, such as birefringence of the solution, are calculated by averaging the optical anisotropy of each macromolecule over all molecular orientations, which are weighted according to the orientation distribution function. The extinction angle and the amount of birefringence are expressed as functions of the velocity gradient and the electric field strength. The behavior of these properties is specifically dependent on the shape and the electric parameters of macromolecule. This method can provide new information about the macromolecular structure.