Li Weizheng, Li Lingling, Zheng Sijie, Liu Ziyang, Zou Xiuyang, Sun Zhe, Guo Jiangna, Yan Feng
Jiangsu Engineering Laboratory of Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, P. R. China.
Adv Mater. 2022 Jul;34(28):e2203049. doi: 10.1002/adma.202203049. Epub 2022 Jun 6.
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.
大多数凝胶和弹性体在共价网络中引入牺牲键以耗散能量。然而，长期循环加载会导致不可逆的疲劳损伤，且无法防止裂纹扩展。此外，由于不可逆的共价交联网络，实现可逆的机械互锁并重新组织聚合物链段以实现离子凝胶的回收和再利用是一项巨大的挑战。在此，主体材料的共价交联被缠结所取代。缠结的微区用作物理交联，同时引入可逆的键相互作用。线性链段和共价网络微球的互穿、缠结和弹性微区提供了机械稳定性，消除了负载下裂纹尖端的应力集中，并在任何负载方向上实现了离子凝胶前所未有的抗撕裂和抗疲劳性能。此外，可逆缠结和非共价相互作用可以解开并重新组合以实现回收和机械再生，并且实现了共价网络微区的可回收性。
