Super Tough, Ultrastretchable Hydrogel with Multistimuli Responsiveness.

The research of hydrogels has been increasingly focused on designing an effective energy dissipation structure in recent years. Here, we report a kind of novel supramolecular cross-linker, which was formed by self-assembling amphiphilic block copolymers with guest groups at the end and vinyl-functionalized cyclodextrin (CD) through host-guest interaction. These cross-linkers could dissipate energy effectively since they combined multiple sacrificial mechanisms across multiscales through physical interactions. The resulted hydrogel shows distinguishing mechanical properties (fracture toughness of 2.68 ± 0.69 MJ/m3 , tension strength of up to 475 kPa, uniaxial stretch over 2100%), remarkable fatigue resistance, and thermal- and light-responsive behaviors.