(558e) 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 of both fundamental and practical importance for diverse hydrogel-based flexible devices. However, these features can hardly be compatible even in elaborately designed hydrogels. Herein we proposed a soft hydrogel network with superior anti-fracture and deformability, which showed good adaption to extremely harsh saline or alkaline environments. The hydrogel network was one-step constructed via hydrophobic homogenous crosslinking of poly (sodium acrylate), which was expected to provide hydrophobic associations and homogeneous crosslinking for effective energy dissipation. The obtained hydrogels were quite soft and deformable (tensile modulus: 20 kPa, stretchability: 3700 %), but showed excellent anti-fracture toughness (fracture toughness: 10.6 kJ m^−2). The energy dissipation mechanism would be further intensified under saline or alkaline environments. The mechanical performance of the hydrophobic crosslinking topology was inspired rather than weakened by extreme 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 showed good performance in reversible deformations (10⁴ th), ion conductivity (20 mS cm^-1), sensing strain, monitoring human motions, and freezing resistance (-20 ℃) under high-saline environments. The hydrogel network showed unique mechanical performance and robust environment adaption, which is quite promising for diverse applications.