Poly(N-ethyl-4-vinylpyridinium bromide)-sodium dodecyl sulfate complexes. Formation and supramolecular organization in salt containing aqueous solutions

Formation and supramolecular organization of poly(N-ethyl-4-vinylpyridinium bromide) (PEVP)-sodium dodecyl sulfate (SDS) complexes in aqueous-salt solutions have been studied. PEVP samples of three polymerization degrees (Pw = 570, 1200 and 2350) were used. For PEVP of lower polymerization degree (Pw = 570) only insoluble complexes were observed in the whole range of the reaction mixture composition studied: Z = [SDS]/[PEVP] ≤ 1. For PEVP of higher polymerization degrees (Pw = 1200 and 2350), water-soluble complexes are formed up to a critical value of the reaction mixture composition, Z, that is similar for both PEVP fractions. It was found that water-soluble complex species are either molecularly dispersed (i.e. each complex particle comprises only one macromolecule) or aggregated (includes about 40 polymer chains and 20,000 surfactant ions) depending on the complex composition. Complex composition, in its turn, was shown to be determined by PEVP polymerization degree and the reaction mixture composition.