Ultra-tough self-healing hydrogel via hierarchical energy associative dissipation

Mechanical robustness is essential to the stability and lifetime of hydrogel based functional materials. Owing to the high water content and homogeneous texture, conventional hydrogels have unsatisfactory strength and elasticity. Methods such as employing tensile-resistant groups and introducing structural heterogeneity have been developed to fabricate tough hydrogels. However, those techniques significantly increased the complexity and cost of material preparation, and only had limited applicability. Here we show ultra-tough hydrogels can be obtained via a unique hierarchical architecture composed of tightly coupled self-assembly units formed in one-pot polymerization reaction. The associative energy dissipation among them exhibits clear correlations with the structure of reactants, which may be rationally designed to yield desired products. Tunable tensile strength, fracture strain and toughness of up to 19.6 MPa, 20000% and 135.7 MJ/cm3 have been achieved, all exceed the best known records. The chemical nature of intermolecular interactions involved in the self-assembly also enables self-healing capability and high underwater stability. Our results demonstrate a universal strategy to synthesis libraries of super-robust hydrogels in a predictable and controllable manner. The superior simplicity, versatility and effectiveness of the present method hold great promise in industrial applications.