Using Periodic Dynamic Polymers to Form Supramolecular Nanostructures

Abstract

ConspectusMany emerging applications including wearable electronics and e-skins, soft robotics and actuators, and biomaterials require material platforms with precisely controlled mechanical, electrical, thermal, and optical properties. The practical realization of devices for these applications is often restricted not by the lack of novel designs but rather by the sparsity of materials with the required properties. Dynamic polymers, which employ both covalent and noncovalent linkages, offer a promising platform for the design of new materials because of their highly tunable chemical structures.In this Account, we highlight our recent work describing the formation of supramolecular nanostructures using periodic dynamic polymers. We discuss similarities and differences between these polymers and well-established research areas, including supramolecular polymers and segmented block copolymers. We highlight the key molecular design considerations driving nanostructure formation and outline exciting potential applications. The key message is that polymers with controlled bond periodicity along their backbone, in contrast to polymers with randomly placed bonds, can extend the robust and complex examples of small-molecule supramolecular assembly to systems comprising long polymer chains. These supramolecularly ordered polymers can exhibit unprecedented material properties.Our recent work suggests that periodic dynamic polymers represent an emerging class of materials in which their well-defined polymer structure leads to ordered microstructures and enhanced material properties. This Account explores this idea and is structured as follows. Section I introduces the concepts of random and periodic dynamic polymers. Section II discusses periodic dynamic polymers in the context of both supramolecular polymers and segmented block copolymers. Section III examines the molecular design rules for spontaneous self-assembly of periodic dynamic polymers into supramolecular nanofibers. Section IV discusses the phenomenon of strain-induced supramolecular structures exhibited by entangled periodic dynamic polymers. Section V concludes with emerging applications for these systems.