An Anti‐Fracture and Super Deformable Soft Hydrogel Network Insensitive to Extremely Harsh Environments

Design of hydrogels with superior flexible deformability, anti‐fracture toughness, and reliable environment adaption is fundamentally and practically important for diverse hydrogel‐based flexible devices. However, these features can hardly be compatible even in elaborately designed hydrogels. Herein soft hydrogel networks with superior anti‐fracture and deformability are proposed, which show good adaption to extremely harsh saline or alkaline environments. The hydrogel network is one‐step constructed via hydrophobic homogenous cross‐linking of poly (sodium acrylate), which is expected to provide hydrophobic associations and homogeneous cross‐linking for energy dissipation. The obtained hydrogels are quite soft and deformable (tensile modulus: ≈20 kPa, stretchability: 3700%), but show excellent anti‐fracture toughness (10.6 kJ m(−2)). The energy dissipation mechanism can be further intensified under saline or alkaline environments. The mechanical performance of the hydrophobic cross‐linking topology is inspired rather than weakened by extremely saline or alkaline environments (stretchability: 3900% and 5100%, toughness: 16.1 and 17.1 kJ m(−2) under saturated NaCl and 6 mol L(−1) NaOH environments, respectively). The hydrogel network also shows good performance in reversible deformations, ion conductivity, sensing strain, monitoring human motions, and freezing resistance under high‐saline environments. The hydrogel network show unique mechanical performance and robust environment adaption, which is quite promising for diverse applications.