Chain Model for Polyelectrolytes. VII. Potentiometric Titration and Ion Binding in Solutions of Linear Polyelectrolytes

The electrostatic potential about a rodlike polyion in an aqueous solution containing added simple electrolyte is calculated by numerical integration of the Poisson-Boltzmann equation. The results are applied to the calculation of the ionic distributions about the polyion and the potentiometric titration curves of polyweak acids. The nature of ion binding is discussed in terms of a molecular model and it is found that the degree of ion binding f* may be expressed as f*=1−(2Ne2/DkTL)−1,where the parameters are defined in the text.