Breaking the Toughness‐Stretchability Trade‐Off in Hydrogels with Dynamic Hydrogen Bonding

ABSTRACT The inherent trade‐off between toughness and stretchability in conventional hydrogels restricts their utility in demanding structural and engineering scenarios. Here, we address this limitation by designing a nanocomposite hydrogel with densified, interfacially bridged network architecture, comprising uniformly dispersed aminopropyl‐hybrid‐phyllosilicate (AHPS) nanosheets within a polyacrylamide (PAM) matrix. A dynamic hydrogen‐bonding network between AHPS and PAM enables efficient energy dissipation during deformation, imparting the material with exceptional mechanical performance. The optimized nanocomposite (3 wt.% AHPS) achieves a toughness of 6.91 MJ/m ³ —a 173‐fold enhancement compared to pristine PAM—and an elongation at break of 3390%, representing a 31‐fold improvement over the unreinforced hydrogel. Furthermore, the reversible breakage and reformation of hydrogen bonds endow the AHPS/PAM hydrogel with outstanding self‐recovery capabilities, retaining structural integrity over repeated stress‐strain cycles. By synergizing a nanoscale interfacial bridging with dynamic hydrogen bonding, this strategy unlocks unprecedented combinations of toughness, stretchability, and resilience, suggesting strong potential as a mechanically robust platform for soft robotics and flexible material systems.