文摘
The pyranine-induced micellization of poly(ethylene glycol)-block-poly(4-vinylpyridine) (PEG114-b-P4VP61) inaqueous solutions and pH-triggered release of pyranine from the complex micelles were studied by dynamic and staticlight scattering, transmission electron microscopy, 1H NMR spectroscopy, and UV-vis spectroscopy. At pH 2, theionized pyranine can ionically cross-link the protonated P4VP block and result in well-defined spherical complexmicelles with a P4VP/pyranine core surrounded by a PEG corona. The ratio of pyranine to pyridyl units can influencethe structure and the properties of the resultant complex micelles. The complex micelles are stable upon dilution andheating but are sensitive to pH changes. pH-triggered release of the incorporated pyranine from the complex micellesdemonstrates that the release behavior is pH-tunable and displays good controlled-release characteristics at pH ~ 4.