Recyclable, Healable, and Tough Ionogels Insensitive to Crack Propagation
Weizheng Li, Lingling Li, Sijie Zheng, Ziyang Liu, Xiuyang Zou, Zhe Sun, Jiangna Guo, and Feng Yan*（严锋）
Jiangsu Engineering Laboratory of Novel Functional Polymeric MaterialsCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123, P. R. China
Adv.Mater. 2022, 2203049
Most gels and elastomers introduce sacrificial bonds in the covalent network to dissipate energy. However, long-term cyclic loading caused irreversible fatigue damage and crack propagation cannot be prevented. Furthermore, because of the irreversible covalent crosslinked networks, it is a huge challenge to implement reversible mechanical interlocking and reorganize the polymer segments to realize the recycling and reuse of ionogels. Here, covalent crosslinking of host materials is replaced with entanglement. The entangled microdomains are used as physical crosslinking while introducing reversible bond interactions. The interpenetrating, entangled, and elastic microdomains of linear segments and covalent-network microspheres provide mechanical stability, eliminate stress concentration at the crack tip under load, and achieve unprecedented tear and fatigue resistance of ionogels in any load direction. Moreover, reversible entanglements and noncovalent interactions can be disentangled and recombined to achieve recycling and mechanical regeneration, and the recyclability of covalent-network microdomains is realized.