Supramolecular polymers at work

Sophisticated polymeric materials with ‘responsive’ properties are beginning to reach the market. The use of reversible, noncovalent interactions is a recurring design principle for responsive materials. Now, recently developed hydrogen-bonding units allow this design principle to be taken to its extreme. Supramolecular polymers, where hydrogen bonds are the only force keeping the monomers together, form materials whose (mechanical) properties respond strongly to a change in temperature or solvent. In this review, we describe the developments that have led to hydrogen-bonded supramolecular polymers and discuss the use of these materials in advanced applications.