TRANSPORT-COEFFICIENTS OF HELICAL WORMLIKE CHAINS .4. INTRINSIC-VISCOSITY OF THE TOUCHED-BEAD MODEL

The intrinsic viscosity of the helical wormlike touched-bead model without excluded volume is evaluated by taking into account the effect of the finite volume of the bead. An empirical interpolation formula for it is presented. This formula is useful for an analysis of experimental data for flexible chains, if the data for low molecular weights are included. Some salient aspects of the behavior of the intrinsic viscosity over a wide range of molecular weight (or contour length) are discussed on the basis of the numerical results. In particular, it is found that the slope of the double-logarithmic plot of the intrinsic viscosity against the molecular weight becomes smaller than one-half as the helical nature becomes strong.