Physical hydrogels composed of polyampholytes demonstrate high toughness and viscoelasticity
Physical hydrogels composed of polyampholytes demonstrate high toughness and viscoelasticity
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DOI：
10.1038/nmat3713
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发表时间：
2013-10-01
期刊：
影响因子：
41.2
通讯作者：
Gong, Jian Ping
中科院分区：
文献类型：
--
作者：
Sun, Tao Lin;Kurokawa, Takayuki;Gong, Jian Ping
水凝胶具有类似于生物组织的柔软湿润特性，作为生物材料备受关注。最近发明的几种坚韧的水凝胶显示了它们作为结构生物材料的潜力，例如软骨。然而，任何给定的应用都需要机械性能的组合，包括刚度、强度、韧性、阻尼、抗疲劳性和自愈性，以及生物相容性。这种组合很少实现。在这里，我们报道了多两性聚合物，具有随机分散的阳离子和阴离子重复基团的聚合物，形成具有多种力学性能的坚韧和粘弹性水凝胶。这种随机性使得离子键的强度分布很广。强键作为永久交联，赋予弹性，而弱键可逆地断裂和重新形成，耗散能量。这些具有超分子结构的物理水凝胶可以通过不同的离子组合在大范围内改变多种机械性能。这种多两性聚合物方法合成简单，并大大增加了应用中坚韧水凝胶的选择。
Hydrogels attract great attention as biomaterials as a result of their soft and wet nature, similar to that of biological tissues. Recent inventions of several tough hydrogels show their potential as structural biomaterials, such as cartilage. Any given application, however, requires a combination of mechanical properties including stiffness, strength, toughness, damping, fatigue resistance and self-healing, along with biocompatibility. This combination is rarely realized. Here, we report that polyampholytes, polymers bearing randomly dispersed cationic and anionic repeat groups, form tough and viscoelastic hydrogels with multiple mechanical properties. The randomness makes ionic bonds of a wide distribution of strength. The strong bonds serve as permanent crosslinks, imparting elasticity, whereas the weak bonds reversibly break and re-form, dissipating energy. These physical hydrogels of supramolecular structure can be tuned to change multiple mechanical properties over wide ranges by using diverse ionic combinations. This polyampholyte approach is synthetically simple and dramatically increases the choice of tough hydrogels for applications.