Examination of the dielectric susceptibility of poly(γ-benzyl-L-glutamate)

Abstract

The published literature on the dielectric susceptibility of poly(γ-benzyl-L-glutamate), in both solid form and in solutions of differing association, has been examined in terms of a many-body, cooperative theory of dielectric response. It is shown that the shape of the susceptibility as a function of frequency is, in a limited manner, sensitive to the degree of association of the α-helical molecule. Of the two types of dipolar tunnelling transitions that can occur between the molecules only the synchronous flip–flop mechanism is sensitive to the association, the single dipolar flip process remaining unperturbed. The examination of a d.c. bias field experiment shows that neither mechanism is sensitive to d.c. fields, but that both the frequency of the maximum dielectric loss and the amplitude of the susceptibility vary in accordance with the predictions of the many-body theory.