| Περίληψη: | We report on the formation and structure development of polyelectrolyte-surfactant complexes, PE-S, of double hydrophilic block copolymers poly(sodium 2-sulfamate-3-carboxylate isoprene)-block-poly(ethylene oxide), PSCI-PEO, and cationic fluorosurfactant, N-(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl)pyridinium chloride, HFDPCl. We compare the behavior of four PSCI-PEO samples differing in comonomer composition and polyisoprene block modification degree. Coassembled core-shell nanoparticles with the core formed by the PSCI/HFDPCl complex and the shell of PEO blocks were characterized by microscopic techniques (cryogenic transmission electron microscopy, atomic force microscopy) and by small-angle neutron scattering. Interactions between PSCI-PEO and HFDPCl were studied by isothermal titration calorimetry. We show that the bulky fluorosurfactant ions drive the coassembly toward structures with less curved interfaces such as cylindrical and wormlike micelles or vesicles. We also demonstrate the role of hydrophobic interactions in the system induced by the presence of unmodified polyisoprene units which in the case of the PSCI-PEO copolymer with a low degree of modification lead to formation of PSCI-PEO micelles and prevent the copolymer from the coassembly with HFDPCl. |
