Nonlinear Viscoelasticity and Toughening Mechanisms in Nanoclay-PNIPAAm Double Network Hydrogels
Nonlinear Viscoelasticity and Toughening Mechanisms in Nanoclay-PNIPAAm Double Network Hydrogels
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DOI：
10.1021/acsmacrolett.3c00083
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发表时间：
2023-04-11
影响因子：
7.015
通讯作者：
Vernerey, Franck J.
中科院分区：
文献类型：
--
作者：
Xu, Lin;Lamont, Samuel C.;Vernerey, Franck J.
我们研究了在不同浓度的共价和物理交联的磁性温度敏感性水凝胶的机械性能。该水凝胶由共价交联的聚（N-异丙基丙烯酰胺）（PNIPAAm）、物理相互作用的纳米粘土颗粒和磁性氧化铁纳米颗粒组成。物理纳米粘土网络表现出很强的粘塑性行为，我们发现，增加纳米粘土含量提高了双重网络材料的强度和韧性。我们调查的行为的凝胶使用非线性粘塑性模型与修改规则的混合物的方法和属性观察到的趋势两个因素：（a）的屈服应力行为的纳米粘土网络和（B）之间的PNIPAAm和纳米粘土的负载分担相互作用。我们的研究结果表明，使用的共价交联剂的质量比和分数的PNIPAAm网络的渗滤之间的强相关性。
We investigate the mechanical properties of a magnetic temperature-sensitive hydrogel at varying concentrations of covalent and physical cross-linking. The hydrogel consists of covalently cross-linked poly(N-isopropylacrylamide) (PNIPAAm), physically interacting nanoclay particles, and magnetic ferric oxide nanoparticles. The physical nanoclay network exhibits strong viscoplastic behavior, and we find that increasing nanoclay content improves both strength and toughness in the double network materials. We investigate the behavior of the gels using a nonlinear viscoplasticity model with a modified rule of mixtures approach and attribute the observed trends to two factors: (a) the yield-stress behavior of the nanoclay network and (b) load-sharing interactions between the PNIPAAm and the nanoclay. Our findings indicate a strong correlation between the mass ratio of covalent cross-linker used and fractional percolation of the PNIPAAm network.