Supramolecular Polymer Brushes Grown by Surface‐Initiated Atom Transfer Radical Polymerization from Cucurbit[7]uril‐based Non‐Covalent Initiators

Polymer brushes are densely grafted, chain end‐tethered assemblies of polymers that can be produced via surface‐initiated polymerization. Typically, this is accomplished using initiators or chain transfer agents that are covalently attached to the substrate. This manuscript reports an alternative route towards polymer brushes, which involves the use of non‐covalent cucurbit[7]uril‐adamantane host–guest interactions to surface‐immobilize initiators for atom transfer radical polymerization. These non‐covalent initiators can be used for the surface‐initiated atom transfer radical polymerization of a variety of water‐soluble methacrylate monomers to generate supramolecular polymer brushes with film thicknesses of more than 100 nm. The non‐covalent nature of the initiator also allows facile access to patterned polymer brushes, which can be produced in straightforward fashion by drop‐casting a solution of the initiator‐modified guest molecules onto a substrate that presents the cucurbit[7]uril host. Surface‐immobilized, initiator‐modified cucurbit[7]uril (CB[7])‐adamantane host–guest complexes allow the growth of supramolecular brushes with thicknesses of >100 nm via atom transfer radical polymerization. The non‐covalent immobilization of the initiator also provides a facile route towards patterned polymer brushes via drop casting of an aqueous solution of an initiator‐modified adamantane derivative onto a CB[7] functionalized substrate.