The structure and sorption properties of a polymer-colloid complex formed by cetylpyridinium cations and polyacrylate anions

The structure and sorption properties of a stoichiometric polymer-colloid complex formed by polyacrylate anions and cetylpyridinium cations were studied. The complex is essentially a cetylpyridinium salt of polyacrylic acid and comprises positively charged surfactant lamellae linked by salt bonds to polyacrylate anions. The aliphatic radicals of cetylpyridinium form a crystalline hexagonal packing inside the lamellae. The polymer-colloid complex has an amphiphilic character and is capable of limited swelling in water and organic solvents of various polarities. The swelling in water and low-polarity organic substances is accompanied by strong modification of the complex structure. During the co-adsorption of saturated vapors of water and low-polarity organic substances, the equilibrium degree of swelling was markedly greater as compared to that following from the additive model.