3D Interlayer Slidable Multilayer Nano-Graphene Oxide Acrylate Crosslinked Tough Hydrogel.
3D Interlayer Slidable Multilayer Nano-Graphene Oxide Acrylate Crosslinked Tough Hydrogel.
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DOI：
10.1021/acs.langmuir.2c00355
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发表时间：
2022-06
期刊：
影响因子：
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通讯作者：
Sihang Liu;Liangbo Xu;Zhefan Yuan;Mei Huang;Tian Yang;Shengfu Chen
中科院分区：
文献类型：
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作者：
Sihang Liu;Liangbo Xu;Zhefan Yuan;Mei Huang;Tian Yang;Shengfu Chen
具有空间结构的三维交联单元的设计对于提高水凝胶的力学性能具有重要意义。然而，几乎所有的纳米复合材料纳入水凝胶被定义为刚性纳米填料，没有进一步讨论的空间结构变化的潜在贡献。在这项工作中，开发了3D纳米化学交联剂多层氧化石墨烯丙烯酸酯（mGOa）作为压力响应性交联剂，以通过层间滑动协同更多的聚合物链对抗加载力来实现低弹性模量和高压缩应力。结果表明，在聚（甲基丙烯酸2-羟乙酯-丙烯酰胺）水凝胶（摩尔比：1：1）中仅用2 mg/mL mGOa纳米化学交联剂交联的水凝胶可以有效地提高在高压缩应变（90.6%）下的机械强度高达14.1 ± 2.1MPa，在初始5%压缩下的弹性模量小于0.03MPa，而用甲基丙烯酸化单层氧化石墨烯（sGOa）或小分子化学交联剂N，N '-亚甲基双丙烯酰胺交联的水凝胶分别只能达到2.3 ± 0.8MPa和1.4 ± 0.4MPa。此外，mGOa交联水凝胶的瞬时模量随着应变的增加而迅速增加到峰值。HcA-mGOa水凝胶的重复压缩测试显示了模量的响应性增加，这是由压缩下的聚合物链的协同作用促进的。这表明mGOa的层间滑动是机械强度增强的关键因素，这为设计坚韧水凝胶提供了新的理论基础。
The design of three-dimensional crosslinked units with a spatial structure is of great significance for improving the mechanical properties of hydrogels. However, almost all the nanocomposites incorporated in hydrogels were defined as rigid nanofillers without further discussion on the potential contribution from the spatial structure change. In this work, the 3D nano chemical crosslinker multilayer graphene oxide acrylate (mGOa) was developed as a pressure-responsive crosslinker to achieve both low elastic modulus and high compression stress by synergizing more polymer chains against the loading force through interlayer sliding. Results showed that the hydrogel crosslinked by only 2 mg/mL mGOa nano chemical crosslinker in the poly(2-hydroxyethyl methacrylate-co-acrylamide) hydrogel (molar ratio: 1:1) can effectively enhance the mechanical strength up to 14.1 ± 2.1 MPa at a high compressive strain (90.6%) with an elastic modulus of less than 0.03 MPa at the initial 5% compression, whereas the hydrogel crosslinked by methacrylated single-layer graphene oxide (sGOa) or a small-molecule chemical crosslinker, N,N'-methylene bisacrylamide, can only reach 2.3 ± 0.8 MPa and 1.4 ± 0.4 MPa, respectively. In addition, the instantaneous modulus of the mGOa crosslinked hydrogel rapidly increased to the peak value with the increase of strain. The repeated compression test of HcA-mGOa hydrogels showed the responsive increase of the modulus, which was promoted by the synergism of polymer chains under compression. This indicated that the interlayer sliding of mGOa is the key contributor to mechanical strength enhancement, which provides a new rationale to design tough hydrogels.