Binding of dodecylpyridinium chloride to anionic copolymers and their complexes

The influence of the charge density of anionic copolymers and different primary polyectrolyte complexes with a negative surface charge on the process of binding to dodecylpyridinium chloride (DoPyCl) was investigated at 25°C by using an electrode selective to the surfactant cation. The binding isotherms thus obtained are indicative of a cooperative binding process, 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 polyanion-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.