Relaxation mechanisms in hydrogels with uniaxially oriented lamellar bilayers
Relaxation mechanisms in hydrogels with uniaxially oriented lamellar bilayers
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DOI：
10.1016/j.polymer.2023.125686
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发表时间：
2023-01-12
期刊：
影响因子：
4.6
通讯作者：
Gong, Jian Ping
中科院分区：
文献类型：
--
作者：
Giustiniani, Anais;Ilyas, Muhammad;Gong, Jian Ping
水凝胶是生物医学应用的绝佳候选者，但往往表现出较差的抗断裂性。该领域的最新发展，例如层状凝胶，旨在提高其机械性能。在这里，我们研究了由自组装聚合物 DGI（衣康酸十二烷基甘油酯）分子的刚性和疏水性双层组成的层状凝胶，这些分子周期性地缠绕在柔软和弹性的聚丙烯酰胺（PAAm）水凝胶（称为 PDGI/PAAm 水凝胶）中，由于其各向异性结构，构成了模拟皮肤和肌肉等生物组织特性的良好模型系统。在本文中，我们根据 PDGI/PAAm 凝胶的结构分析了其动态机械性能，并检查了不同的能量耗散机制。通过拉伸测试，我们首次证明松弛过程是由于 PDGI 双层内物理键的断裂造成的，特征时间约为 10 秒。
Hydrogels are excellent candidates for biomedical applications but often show poor resistance to fracture. Recent development in the field, such as lamellar gels, aimed at improving their mechanical properties. Here, we study lamellar gels composed of rigid and hydrophobic bilayers of self-assembled polymeric DGI (Dodecyl Glyceryl Itaconate) molecules periodically intertwined in soft and elastic polyacrylamide (PAAm) hydrogel (called PDGI/PAAm hydrogels), which, thanks to their anisotropic structure, constitute good model systems to mimic the properties of biotissues such as skin and muscle. In this paper, we present an analysis of the dynamic mechanical properties of PDGI/PAAm gels depending on their structure, along with an examination of the different energy dissipation mechanisms at play. Using tensile testing, we show for the first time that the relaxation process is due to the rupture of physical bonds within the PDGI bilayers, with a characteristic time in the order of 10 s.