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

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/m³-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.