PH OF WEAK POLYACID SOLUTIONS IN THE PRESENCE OF MONO-VALENT AND DIVALENT COUNTERIONS

The pH of weak polyacid solutions containing mono- and/or divalent counterions has been treated by use of the solution of the Poisson-Boltzmann equation applied to the parallel-rod cell model. The dielectric saturation effect is taken into account in the calculation. Agreement between the theory and experimental data is generally satisfactory, particularly if the comparison is carried out at a constant charge density. If the charge density of the polyelectrolyte is low and the ionic strength is high, however, the agreement between the theory and experiments is not satisfactory, probably because the parallel-rod cell model fails. © 1979, American Chemical Society. All rights reserved.