Effect of Relative Strength of Two Networks on the Internal Fracture Process of Double Network Hydrogels As Revealed by in Situ Small-Angle X-ray Scattering

Double network hydrogels (DN gels) exhibit extraordinarily high strength and toughness by interplay of the two contrasting networks: the rigid, brittle network serves as a sacrificial bond that fractures at a relatively low strain, while the soft, stretchable network serves as hidden length that sustains stress by large extension afterward. The internal fracture process of the brittle network strongly depends on the relative strength of the two...