Intrinsic viscosity of wormlike polymer chains

The intrinsic viscosity of wormlike polymer chains has been calculated using the Kirkwood–Riseman method. The chain statistics are taken from the Hermans and Ullman analysis of the Kratky–Porod model. Results are obtained for several degrees of chain extension for chains of varying molecular weight as a function of the degree of hydrodynamic interaction. The finite cross section of the chain is explicitly introduced in the model. The limiting results of the rigid rod and of the random coil are obtained at low and high degrees of chain coiling, respectively. Application of this model to DNA leads to a Kuhn statistical bond length of 1020 Å. The model was also applied to flexible polyelectrolytes in solutions of low salt concentration and to cellulose nitrate. A method of using the tabulated results for estimates of the degree of coiling of other polymer systems is described.