pH-dependent micellization of poly(2-vinylpyridine)-block-poly(ethylene oxide)

This paper reports the spontaneous micelle formation by PVP-b-PEO in aqueous solutions when increasing the pH from acidic to neutral or basic conditions. The micellization process is completely reversible if the pH is cycled above and below the critical pH. This polymer is also comicellized with homopolymer poly(2-vinylpyridine) (PVP). The properties of the PVP-b-PEO or PVP/PVP-b-PEO micelles seem to defy the condition of closed association which has been demonstrated in many block copolymer micelle systems. It is argued that this is because of the kinetics of PVP aggregation with simultaneous stabilization by PVP-b-PEO.