Phase-Pinned Bicontinuous Structures Reconciling with the Superior Fracture Toughness and Reusability of Ionic Elastomers
Zibi Wang, Xiaoxu Liu, Fahu Yang, Xinxin Li, Haipeng Li, Dong Liu, Fei Chen
Abstract
Imperative integrations of high fracture toughness and reusability are seemingly contradictory in ionic elastomers due to their intrinsically opposite network designs. Such combinations, however, are paramount for soft electronics, tissue engineering scaffolds, and ionic skins with a long service life. Here, we engineer a supramolecular ionic elastomer with phase-pinned bicontinuous structures to reconcile these incompatible properties through elaborately regulating the association dynamics and chain entanglement. The continuous liquid-crystal phase with sticky fluorine-chain association provides a high fracture energy barrier and effective energy dissipation, while the continuous percolating phase with flexible chain entanglement enables good stretchability and elasticity. Moreover, these bicontinuous phases are pinned by dynamic intra/interphase noncovalent interactions, facilitating the load distribution and network reconfiguration. Therefore, the crack growth under single and cyclic loads is suppressed, fulfilling the brilliant toughness (60.3 MJ m –3 ), fracture energy (63.9 KJ m –2 ), fatigue threshold (1.56 KJ m –2 ), and ultrastretchability (∼3040%) requirements, while achieving excellent recyclability and self-healability through reversible network reconstruction.