Host–guest driven supramolecular assembly of reversible comb-shaped polymers in aqueous solution

Abstract

We report an original strategy towards supramolecular assembly of reversible comb-shaped polymers in aqueous solution through β-cyclodextrin–adamantane (β-CD–Ada) host–guest inclusion. Ada-functionalized poly(acrylic acid) grafts were generated by RAFT polymerization mediated by an adamantane-α-functionalized RAFT agent. A β-CD-grafted backbone was obtained by a two-step procedure: alkyne-functionalized backbones were first generated by RAFT polymerization of trimethylsilyl propargyl methacrylate and subsequently converted in a host system by CuAAC with azide-functionalized β-CD. The self-assembly between a β-CD-grafted polymer backbone and Ada-functionalized grafts was highlighted by ¹H 2D NOESY NMR in D₂O and by DLS. The reversible character of the host–guest association between the complementary macromolecular blocks was demonstrated by DLS through the addition of competing free β-CD.