Sulfone-Bond-Toughened Multifunctional Hydrogels with Ion-Modulated Fluorescence and Mechanical Properties

Sulfone bonding is an emerging dipole-dipole interaction between sulfone groups. Herein, sulfone bonding is used for the first time for engineering tough hydrogels. Sulfone-bond-toughened hydrogels are prepared by copolymerizing acrylamide with a sulfone-functionalized monomer. The integration of sulfone groups establishes cooperative supramolecular interactions between sulfone bonding and hydrogen bonding, endowing the hydrogels with tailorable mechanical properties, thermoresponsiveness, and clustering-induced fluorescence, which are readily modulated by varying the monomer composition. Moreover, the unique ion-responsiveness of sulfone bonding allows ion-responsive engineering of these hydrogel properties. Capitalizing on the ion-modulated fluorescence and thermal-responsive transitions of these hydrogels, we demonstrate their potential for rewritable information display applications. This work provides new insights into noncovalently toughened hydrogels and opens avenues for designing supramolecular networks based on sulfone bonding.