The release of monovalent counterions by addition of divalent counterions in coulombic interaction system of polyions (II)

In this work, the increase in activity. Deltaa+ of a monovalent counterion (Na+) resulting from the addition or a divalent ion (Cu2+) was experimentally investigated in sulfate or sulfonate polyelectrolyte solutions. It was found that in the case of polyvinylsulfonate, a+ was expressed by Deltaa+ = Delta(C++ -a++). where C(++) and a(++) represent the molar concentration and activity of added Cu2+ respectively, while in the case of dextran sulfate, the expression or Deltaa+ became Deltaa+ =2Delta(C++-a++). Considering that interactions between these cations and sulfate or sulfonale groups are Durely electrostatic, these results were analyzed in relation to the conformation of the polyelectrolytes.