Pyrene-Based Macrocrosslinkers with Supramolecular Mechanochromism for Elastic Deformation Sensing in Hydrogel Networks

Excimer-containing polymers with supramolecular mechanochromism are an attractive and well-investigated class of mechanoresponsive materials. However, only recently steps toward mechanophore-like mechanochromic systems that are anchored within the parent polymer structure and that show defined optical transitions on the molecular scale have been reported. However, the multi-step syntheses of these constructs are tedious. Here we report the development of a series of pyrene-based macrocrosslinkers that display supramolecular mechanochromism and are readily synthesized from mostly commercial reagents. We incorporate the water-soluble macrocrosslinkers in hydrogel networks and demonstrate their reversible mechanochromic behavior in the elastic deformation regime.