Sytze J. Buwalda, Pieter J. Dijkstra, Jan Feijen
Journal of Polymer Science 2012
The aqueous solution behavior and thermoreversible gelation properties of pyridine-end-functionalized poly(ethylene glycol)–poly(L-lactide) (PEG–(PLLA)8–py) star block copolymers in the presence of coordinating transition metal ions were studied. In aqueous solutions, the macromonomers self-assembled into micelles and micellar aggregates at low concentrations and formed physically crosslinked, thermoreversible hydrogels above a critical gel concentration (CGC) of 8% w/v. In the presence of transition metal ions like Cu(II), Co(II), or Mn(II), the aggregate dimensions increased. Above the CGC, the gel–sol transition shifted to higher temperatures due to the formation of additional crosslinks from intermolecular coordination complexes between metal ions and pyridine ligands. READ MORE...