Further Discussion on Method to Determine the Intrinsic Viscosity of Polyelectrolyte Solution

According to the method presented by Wolf,the intrinsic viscosity of polyelectrolyte can be obtained either by extrapolating the generalized intrinsic viscosity {η} towards zero concentration C or by the initial slope of the dependence of the logarithm of the relative viscosity lnηr on polymer concentration C.Our research indicates that the value of the generalized intrinsic viscosity {η},the apparent intrinsic viscosity [η]app and the reduced viscosity ηsp/C become the same as extrapolating concentration C to zero.Furthermore,the viscosity measurement indicates that the dependence of {η},[η]app and ηsp/C with concentration C is just the same in extremely diluted polyelectrolyte solutions.This suggests that the method to determine the intrinsic viscosity of polyelectrolyte by extrapolating the generalized intrinsic viscosity {η} towards zero concentration C is essentially just the same as extrapolating ηsp/C towards zero concentration C in the Huggins ηsp/C versus C plot which is traditionally used.