Effects of symmetric and antisymmetric stress tensors on N- and α-dielectric relaxations

Abstract

We present a generalized hydrodynamic model for dielectric relaxation to describe the effect of spatial inhomogeneities in the polarization fluctuations in viscoelastic fluids. The model is a generalization of the simple Debye relaxation equation with the addition of the gradient of the total stress tensor. The two known modes of relaxation, N- and α-absorption can be incorporated in the model semiquantitatively, since we do not know the actual parameters involved. The comparison between our results and the experimental response reported for the N- and α-modes in polymers, shows that the predicted intensities of the loss peaks are well represented. However, at lower and higher frequencies the predicted curves deviate from the experimental ones.