NUMERICAL AND EXPERIMENTAL STUDIES OF TERRITORIAL BINDING OF COUNTERIONS IN POLYELECTROLYTE SOLUTIONS INCLUDING THE ADDED SALT CASE

This paper provides an extension of a procedure for calculating counte rion binding ratios in a polyelectrolyte solution based on the Poisson -Boltzmann formulation of territorial counterion binding to include th e presence of excess salt of the counterion. It is an extension of an earlier version which dealt with two counterions with different charge numbers without excess salt. The relative binding parameter of sodium to poly(galacturonic acid) as a function of the degree of neutralizat ion in the presence of excess sodium chloride is determined by Na-23 n .m.r. and compared with the numerical results from the Poisson-Boltzma nn and the Manning condensation theories. Agreement is found with the Poisson-Boltzmann results at degrees of neutralization greater than th e critical condensation point predicted by the Manning theory. Qualita tive elements of both theories appear in the experimental results.