[Calculation of the intrinsic viscosity of synthetic and biological polyelectrolytes of various rigidity].

On the basis of the excluded-volume effect theory for nonionic polymer molecules developed by Alexandrowicz semi-empirical formulas for calculation of the intrinsic viscosity [eta] of polyelectrolytes of various rigidity are proposed. The expression for the second virial coefficient of gas consisting of cylindrical particles is used for the determination of explicit form of the effective excluded volume of the segment upsilon0. In addition the alteration of Flory's parameter phi (epsilon) by the expansion of a macromolecule, and the alteration of thermodynamic rigidity A of the polyelectrolyte molecule in the range of low ionic strengths mu have been taken into account. All that leads to good agreement between calculated and experimental values of [eta] of polyelectrolytes under consideration, i. e. native and denatured DNA and poly (acrylic acid), in a wide range of mu. The calculated dependence A = A (mu) providing the best agreement between the theoretical and experimental values of [eta], also describes reasonably the experimental dependence A = A (mu) obtained from the macromolecule's optical anisotropy measurements for native DNA or from unperturbed dimensions of the macromolecule, determined on the basis of the Stockmayer and Fixman equation for denatured DNA.