Flow Induced Ordered State of Helical Poly-Benzyl-L-Glutamate

Summary

Dielectric constant of α-helical poly-benzyl-L-glutamate (PBLG) is measured in the presence of a velocity gradient using rotating cylindrical electrodes. The electric field is applied across the annular gap between electrodes and the vectors of the mechanical and the electrical forces are perpendicular to each other. The dielectric constant decreases with the increasing velocity gradient, as long as the frequency is sufficiently low. When the frequency is increased, the dielectric constant increases slightly and moreover, the dielectric constant is no longer affected by the velocity gradient if the frequency is further increased. In the presence of a sufficiently high velocity gradient, PBLG solutions exhibit a considerably different dielectric relaxation from that without the velocity gradient. A semi-empirical explanation is presented to account for the behavior of polar molecules in a mechanical field and an electrical field.