Guest release and solution behavior of a hydrogen-bonding physical micelle during chemoresponsive shell disruption

摘要: Abstract The guest release and solution behavior during shell disruption of a polymeric nanocapsule are described. Hyperbranched polyethylenimine (PEI, Mn = 10 000) is chemically functionalized with multiple DAD hydrogen-bonding motifs (D A: donor acceptor), leading to PEI232–(DAD)x (3) (x = 93 (3a), x = 46 (3b), x = 23 (3c), x = 12 (3d)). Meanwhile, polyethylene oxide (Mn = 2 200) end-capped thymine moieties (PEO–ADA) (4). Mixing the complementary 3 4 (DAD/ADA = 1) leads physical micelle (3·4) in apolar media, resulting can completely irreversibly transfer ionic water-soluble Congo red (CR) into chloroform phase by encapsulation. Experiment proves that exist as pseudo-unimolecular (p-UIM, meaning one PEI micelle) or aggregate, depending on density. As result, 3b·4 generally exists p-UIM while 3d·4 only very narrow range concentrations. critical aggregation concentration (CAC) also dependent core structure micelle, thus when residual amines 3b transformed amide, 5b·4 shows low CAC. Small chemicals bearing motif compete bind PEO–ADA destruct p-UIM, precipitation along CRs. CR has strong acid–base interaction but basicity reduced amidation, partial CRs be released water phase.