Anti-fatigue-fracture hydrogels
Anti-fatigue-fracture hydrogels
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DOI：
10.1126/sciadv.aau8528
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发表时间：
2019-01-01
期刊：
影响因子：
13.6
通讯作者：
Zhao, Xuanhe
中科院分区：
文献类型：
--
作者：
Lin, Shaoting;Liu, Xinyue;Zhao, Xuanhe
水凝胶在设备和机器中的新兴应用要求水凝胶在循环机械载荷下保持鲁棒性。尽管已经使水凝胶在单次机械载荷循环下具有抵抗断裂的韧性，但是这些增韧的凝胶在多次载荷循环下仍然遭受疲劳断裂。报道的合成水凝胶的疲劳阈值为1至100 J/m（2）的量级。我们建议，设计抗疲劳断裂水凝胶需要使疲劳裂纹遇到和断裂物体的能量比断裂单层聚合物链的能量高得多。我们证明了在水凝胶中可控地引入结晶度可以大大提高其抗疲劳断裂性能。溶胀状态下结晶度为18.9重量%的聚乙烯醇（PVA）的疲劳阈值可超过1000 J/m2。
The emerging applications of hydrogels in devices and machines require hydrogels to maintain robustness under cyclicmechanical loads. Whereas hydrogels have been made tough to resist fracture under a single cycle of mechanical load, these toughened gels still suffer from fatigue fracture under multiple cycles of loads. The reported fatigue threshold for synthetic hydrogels is on the order of 1 to 100 J/m(2). We propose that designing anti-fatigue-fracture hydrogels requires making the fatigue crack encounter and fracture objects with energies per unit area much higher than that for fracturing a single layer of polymer chains. We demonstrate that the controlled introduction of crystallinity in hydrogels can substantially enhance their anti-fatigue-fracture properties. The fatigue threshold of polyvinyl alcohol (PVA) with a crystallinity of 18.9 weight % in the swollen state can exceed 1000 J/m(2).