Stress-relaxation behavior in gels with ionic and covalent crosslinks
Stress-relaxation behavior in gels with ionic and covalent crosslinks
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DOI：
10.1063/1.3343265
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发表时间：
2010-03-15
影响因子：
3.2
通讯作者：
Suo, Zhigang
中科院分区：
文献类型：
--
作者：
Zhao, Xuanhe;Huebsch, Nathaniel;Suo, Zhigang
海藻酸盐水凝胶中的长链聚合物可以通过离子或共价交联形成网络。研究表明，交联类型对凝胶的应力松弛行为有显著影响。在只有离子交联的凝胶中，应力主要通过离子交联的断裂和随后的重整来松弛，松弛的时间尺度与样品的大小无关。相比之下，在只有共价交联的凝胶中，应力主要通过水的迁移而松弛，并且随着样品尺寸的增加松弛速度减慢。讨论了这些观察结果的含义。
Long-chained polymers in alginate hydrogels can form networks by either ionic or covalent crosslinks. This paper shows that the type of crosslinks can markedly affect the stress-relaxation behavior of the gels. In gels with only ionic crosslinks, stress relaxes mainly through breaking and subsequent reforming of the ionic crosslinks, and the time scale of the relaxation is independent of the size of the sample. By contrast, in gels with only covalent crosslinks, stress relaxes mainly through migration of water, and the relaxation slows down as the size of the sample increases. Implications of these observations are discussed.