Herein

the synthesis of an -nlinear-hyperbranched supramolecular block copolymer was reported.First

a linear polymer PMMA-AZO composed of poly(methyl methacrylate) with an azobenzene group at the end was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization.Secondly

a hyperbranched polymer CD-g-HPG composed of hyperbranched polyglycerol with a -cyclodextrin group at the focal point was synthesized by ring-opening multibranching polymerization (ROMBP).Then

the linear PMMA-AZO and hyperbranched CD-g-HPG were conjugated together through the specific CD/AZO host-guest interactions

leading to the formation of amphiphilic linear-hyperbranched supramolecular block copolymer PMMA-b-HPG.The supramolecular polymer of PMMA-b-HPG can be grafted onto gold surface to form self-assembled monolayer through SAu bond generated from the end of trithiocarbonate group

which is introduced into PMMA-AZO by chain transfer agent used in RAFT polymerization.As a result

the modified surface exhibits a hydrophilic feature.When exposed to UV light

however

the hydrophilic CD-g-HPG polymers are dropped off from the surface because of the dissociation of AZO/CD complex

and then the surface turns into hydrophobic.Further immersing the gold surface into CD-g-HPG solution

a hydrophilic surface can be restored.In this way

a modified gold surface which can be tuned reversibly between hydrophilic and hydrophobic under light stimuli was prepared.