Supramolecular polymers: Recent advances based on the types of underlying interactions

Supramolecular polymers are, in broad brushstrokes, self-assembled structures built up from small building blocks via the use of noncovalent interactions. In favorable cases, supramolecular polymers embody the best features of covalent polymers while displaying unique reversibility, responsiveness, adaptiveness, and stability. This has made them of interest across a wide variety of fields, from molecular devices to sensors, drug delivery, cell recognition, and environmentally friendly materials systems. This review is concerned with the determinants that underlie supramolecular polymer construction, specifically the driving forces that have been exploited to create them. To date, nearly the full range of known noncovalent interactions (e.g., hydrogen-bonding, electrostatic interactions, charge transfer effects, and metal coordination, among others) has been exploited to create supramolecular polymers. Typically, one or more types of interactions is used to link appropriately designed monomers. The choice of noncovalent interaction can have a significant influence on the structure and function of the resulting supramolecular polymers. Understanding the connections between the forces responsible for the assembly of supramolecular polymers and their properties provides the foundation for further advances in this fast-moving field. Given the above, this review will discuss recent progress in the rapidly advancing field of supramolecular polymers organized by the types of underlying interactions. An overview of future challenges and opportunities for supramolecular polymers, including their formation, characterization, and applications, is also provided.