The electric polarization of rod-like,charged macromolecules

The polarizability in the longitudinal direction of rod-like, highly charged macromolecules has been evaluated. A simple model, emphasizing the discrete distribution of the fixed charges along the macromolecule, but neglecting interionic repulsion, has been used to calculate the statistical distribution of the counterions which gives rise to this polarization. For weak electric fields the expression obtained for the polarizability is analogous to that previously derived by Schwarz, although it contains less implicit information about the temperature dependence and the influence of the valency of the counterions. The possibility that saturation effects may appear with high electric fields is left open. An approximate formula for the relaxation time of the longitudinal polarization is also derived.