Experiments on Magnetic Orientation of Liquid Crystals of Poly-γ-Benzyl-L-Glutamate

Abstract

Orientation of poly-γ-benzyl-L-glutamate under magnetic field has been measured in liquid-crystalline solution and in film, cast and dried from the solution, by means of optical and electrostatic methods. The orientation which is in the direction of the external field is of an antiparallel type and proposed to be due to induced magnetic dipoles of the side chain groups of the polypeptide molecules. Although the orientation is poor in solution, it is striking in film, and some cooperative behavior of the permanent electric dipoles in a system of the molecular clusters of the polypeptide and of the solvent molecules, which becomes especially prominent as the solution is dried up, is suggested to be involved. Some wall effects from the surfaces of the optical cell used, however, make it difficult of detect true magnetic orientation in solution.