A dual-modality photoswitchable supramolecular polymer.

Covalent or noncovalent linked polymers with stimuli-responsive properties have been well researched as a kind of advanced functional materials. However, little effort has been devoted to establishing a bridge for switching between covalent polymers and noncovalent polymers. Actually, such unitive system is promising because it can combine their chemical advantages of two types of polymers in a single and tunable platform. Herein, by taking advantage of reversible photodimerization of coumarins and host-guest assemblies with γ-cyclodextrin (γ-CD), we demonstrate a simple and effective way to construct a dual-modality supramolecular polymer, which can be switched between a noncovalent polymer and its corresponding covalent polymer in response to light stimuli. Moreover, this unique switchable polymer can also be employed to construct a dual-stimuli responsive supramolecular hydrogel with the surfactant cetyl trimethylammonium bromide (CTAB). This methodology establishes a bridge between the two "polymer mansions" and is promising to open a new class of photoswitchable materials.