Highly stretchable and tough hydrogels.
Highly stretchable and tough hydrogels.
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DOI：
10.1038/nature11409
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发表时间：
2012-09-06
期刊：
影响因子：
64.8
通讯作者：
Suo, Zhigang
中科院分区：
文献类型：
--
作者：
Sun, Jeong-Yun;Zhao, Xuanhe;Illeperuma, Widusha R. K.;Chaudhuri, Ovijit;Oh, Kyu Hwan;Mooney, David J.;Vlassak, Joost J.;Suo, Zhigang
水凝胶被用作组织工程的支架、药物输送的载体、光学和流体的致动器，以及用于生物学研究的细胞外基质模型。然而，水凝胶的应用范围往往受到其机械性能的严重限制。大多数水凝胶不表现出很高的延伸性；例如，当海藻酸水凝胶拉伸到大约其原始长度的1.2倍时，它就会破裂。一些合成弹性水凝胶的拉伸范围在10-20之间，但在含有缺口的样品中，这些值显著降低。大多数水凝胶是脆性的，断裂能约为10 J m−2(参考文献2)。)，相比之下，软骨的∼1,000 J m−2和天然橡胶的∼10,000 J m−2。人们致力于合成机械性能更好的水凝胶；某些合成凝胶的断裂能已达到100-1,000 J m−2(参考文献，，)。在这里，我们报道了由形成离子和共价交联网络的聚合物合成水凝胶。尽管这种凝胶含有90%的水，但它们可以拉伸到初始长度的20倍以上，断裂能为∼9,000 J m−2。即使是含有缺口的样品，拉伸也可以达到17。我们将凝胶的韧性归因于两种机制的协同作用：通过共价交联键网络的裂缝桥接，以及通过解压离子交联键网络的滞后。此外，共价交联网络保留了初始状态的记忆，因此大变形在卸载时被移除。未拉链的离子交联物会造成内部损伤，可通过重新拉链进行修复。这些凝胶可以作为模型体系来探索变形和能量耗散机理，扩大水凝胶的应用范围。
Hydrogels are used as scaffolds for tissue engineering, vehicles for drug delivery, actuators for optics and fluidics, and model extracellular matrices for biological studies. The scope of hydrogel applications, however, is often severely limited by their mechanical behaviour. Most hydrogels do not exhibit high stretchability; for example, an alginate hydrogel ruptures when stretched to about 1.2 times its original length. Some synthetic elastic hydrogels,have achieved stretches in the range 10–20, but these values are markedly reduced in samples containing notches. Most hydrogels are brittle, with fracture energies of about 10 J m−2(ref. ), as compared with ∼1,000 J m−2for cartilage and ∼10,000 J m−2for natural rubbers. Intense efforts are devoted to synthesizing hydrogels with improved mechanical properties,,,,,,,; certain synthetic gels have reached fracture energies of 100–1,000 J m−2(refs , , ). Here we report the synthesis of hydrogels from polymers forming ionically and covalently crosslinked networks. Although such gels contain ∼90% water, they can be stretched beyond 20 times their initial length, and have fracture energies of ∼9,000 J m−2. Even for samples containing notches, a stretch of 17 is demonstrated. We attribute the gels’ toughness to the synergy of two mechanisms: crack bridging by the network of covalent crosslinks, and hysteresis by unzipping the network of ionic crosslinks. Furthermore, the network of covalent crosslinks preserves the memory of the initial state, so that much of the large deformation is removed on unloading. The unzipped ionic crosslinks cause internal damage, which heals by re-zipping. These gels may serve as model systems to explore mechanisms of deformation and energy dissipation, and expand the scope of hydrogel applications.
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影响因子：
5.5
作者：
Kong, HJ;Wong, E;Mooney, DJ
通讯作者：
Mooney, DJ
影响因子：
5.5
作者：
Sakai, Takamasa;Matsunaga, Takuro;Chung, Ung-il
通讯作者：
Chung, Ung-il
DOI：
10.1126/science.1171643
发表时间：
2009-06-26
期刊：
Science (New York, N.Y.)
影响因子：
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作者：
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通讯作者：
Zandstra PW
影响因子：
5.5
作者：
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通讯作者：
Gong, J. Ping
影响因子：
4.4
作者：
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通讯作者：
Ronsin, O.