Poly(ethylene glycol) brush--poly(-vinylpyrrolidone)-based double hydrophilic block copolymer particles crosslinked crystalline α-cyclodextrin domains.

Self-assembly of block copolymers is a significant area of polymer science. The self-assembly of completely water-soluble block copolymers is of particular interest, albeit a challenging task. In the present work the self-assembly of a linear-brush architecture block copolymer, namely poly(-vinylpyrrolidone)--poly(oligoethylene glycol methacrylate) (PVP--POEGMA), in water is studied. Moreover, the assembled structures are crosslinked α-CD host/guest complexation in a supramolecular way. The crosslinking shifts the equilibrium toward aggregate formation without switching off the dynamic equilibrium of double hydrophilic block copolymer (DHBC). As a consequence, the self-assembly efficiency is improved without extinguishing the unique DHBC self-assembly behavior. In addition, decrosslinking could be induced without a change in concentration by adding a competing complexation agent for α-CD. The self-assembly behavior was followed by DLS measurement, while the presence of the particles could be observed cryo-TEM before and after crosslinking.