Water-soluble complexes formed by poly(2-vinylpyridinium)-block-poly(ethylene oxide) and poly(sodium methacrylate)-block-poly(ethylene oxide) copolymers

Formation of interpolyelectrolyte complexes (IPEC) by mixing protonated pol y(2-vinyl-pyridine)-bloch-poly(ethylene oxide) (P2VP-b-PEO) with neutralize d poly(methacrylic acid)-block-poly(ethylene oxide) (PMAA-b-PEO) has been i nvestigated in water. It was observed that (i) IPEC are formed in a limited pH range, which is controlled by the degree of ionization of the PMAA and P2VP blocks; (ii) IPEC self-assemble to form the core of monodisperse spher ical micelles surrounded by a corona of PEO blocks; (iii) IPEC are salt-sen sitive, falling apart above a critical salt concentration; (iv) IPEC are no t observed at high pH, but micelles are formed by the P2VP-b-PEO copolymers , which contain an uncharged P2VP core surrounded by a PEO corona; (v) IPEC are not observed at low pH, but the PMAA-b-PEO diblocks aggregate into mic elles, the core of which is formed by a hydrogen-bonded complex between PMA A and PEO; and (vi) these PMAA-b-PEO micelles, which are temperature-sensit ive, show a complete reorganization of the micellar core above a critical t emperature.