Material Innovation Research Center (MIRC) and Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan.
AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory (OPERANDO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan.
Science. 2021 Jun 4;372(6546):1078-1081. doi: 10.1126/science.aaz6694.
Most tough hydrogels are reinforced by introducing sacrificial structures that can dissipate input energy. However, because the sacrificial damage cannot rapidly recover, the toughness of these gels drops substantially during consecutive cyclic loadings. We propose a damageless reinforcement strategy for hydrogels using strain-induced crystallization. For slide-ring gels in which polyethylene glycol chains are highly oriented and mutually exposed under large deformation, crystallinity forms and melts with elongation and retraction, resulting both in almost 100% rapid recovery of extension energy and excellent toughness of 6.6 to 22 megajoules per cubic meter, which is one order of magnitude larger than the toughness of covalently cross-linked homogeneous gels of polyethylene glycol.
大多数坚韧的水凝胶通过引入牺牲结构来增强，这些牺牲结构可以耗散输入的能量。然而，由于牺牲损伤不能迅速恢复，因此在连续的循环加载过程中，这些凝胶的韧性会大大降低。我们提出了一种使用应变诱导结晶的水凝胶无损伤增强策略。对于滑动环凝胶，其中聚乙二醇链在大变形下高度取向并相互暴露，结晶形成并随拉伸和收缩而熔化，这导致了几乎 100%的延伸能量的快速恢复，以及 6.6 至 22 兆焦耳/立方米的优异韧性，比聚乙二醇的共价交联均相凝胶的韧性高出一个数量级。
