Binding of dodecylpyridinium chloride to anionic copolymers and their complexes

The influence of the charge density of anionic copolymers and different pri mary polyectrolyte complexes with a negative surface char ge on the process of binding to dodecyl-pyridinium chloride (DoPyCl) was investigated at 25 degrees C by using an electrode selective to the surfactant cation. The bin ding isotherms thus obtained are indicative of a cooperative binding proces s, which depends mainly on the charge density of the polyanion used On the other hand cooperativity is hardly evident at all in the case of primary po lyanion-polycation complexes. Static light-scattering measurements support the theory that the charge density of the polyelectrolytes used influences the structural parameters of the primary complex aggregates.