Colloidal complexes of perfluorooctadecanoic acid with cationic copolymers

Five solid complexes of poly[(diallyl dimethylammonium chloride)-co-(N-methyl-N-vinylacetamide)] with perfluorooctadecanoic acid were prepared at 1:1 stoichiometry. Remarkably low surface energies, as determined by contact angle measurements, were attributed to a strong enrichment of complex surfaces with CF3 groups. By increasing of the charge density of the polyelectrolyte, the surface energy decreased from 14 to 9 mN/m. As determined by small angle X-ray scattering, the solid complexes show a mesomorphic structure. A columnar liquid crystalline-like structure with columns consisting of stacks of disklike micelles, two-dimensionally ordered in hexagonal arrays, is suggested. The thermal stability of the structures is explained by Coulomb interactions between diallyldimethylammonium groups and carboxylate ions.