Hybrid Polymer-Network Hydrogels with Tunable Mechanical Response
Hybrid Polymer-Network Hydrogels with Tunable Mechanical Response
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DOI：
10.3390/polym8030082
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发表时间：
2016-03-01
期刊：
影响因子：
5
通讯作者：
Seiffert, Sebastian
中科院分区：
文献类型：
--
作者：
Czarnecki, Sebastian;Rossow, Torsten;Seiffert, Sebastian
通过物理和共价聚合物交联两者构建的杂化聚合物网络凝胶联合收割机结合了这两种交联类型的优点：它们表现出高机械强度沿着优异的断裂韧性和延展性。如果这些材料被广泛变形，它们的物理交联可以断裂，使得应变能被耗散，并且不可逆断裂仅限于高应变。这种能量耗散机制由物理交联贡献的动力学和热力学决定。在本文中，我们提出了一种基于聚乙二醇（PEG）的材料工具包，以合理和定制的方式控制这些贡献。我们形成了定义明确的共价聚合物网络凝胶与规则分布的额外的超分子机械融合链接，其连接的强度可以调整，而不影响主要的聚合物网络组合物。这是可能的，因为超分子的融合链接是基于三联吡啶-金属络合，使得仅仅选择的融合连接的金属离子调整其动力学和热力学的络合-解络合，这直接影响的混合凝胶的机械性能。我们使用振荡剪切流变学来证明这种合理的控制和增强的混合凝胶的机械性能。此外，静态光散射揭示了它们高度规则和明确的聚合物网络结构。由于两者的结果，本方法为制备具有合理设计性能的混合聚合物网络凝胶提供了一种简单可靠的概念。
Hybrid polymer-network gels built by both physical and covalent polymer crosslinking combine the advantages of both these crosslinking types: they exhibit high mechanical strength along with excellent fracture toughness and extensibility. If these materials are extensively deformed, their physical crosslinks can break such that strain energy is dissipated and irreversible fracturing is restricted to high strain only. This mechanism of energy dissipation is determined by the kinetics and thermodynamics of the physical crosslinking contribution. In this paper, we present a poly(ethylene glycol) (PEG) based material toolkit to control these contributions in a rational and custom fashion. We form well-defined covalent polymer-network gels with regularly distributed additional supramolecular mechanical fuse links, whose strength of connectivity can be tuned without affecting the primary polymer-network composition. This is possible because the supramolecular fuse links are based on terpyridine-metal complexation, such that the mere choice of the fuse-linking metal ion adjusts their kinetics and thermodynamics of complexation-decomplexation, which directly affects the mechanical properties of the hybrid gels. We use oscillatory shear rheology to demonstrate this rational control and enhancement of the mechanical properties of the hybrid gels. In addition, static light scattering reveals their highly regular and well-defined polymer-network structures. As a result of both, the present approach provides an easy and reliable concept for preparing hybrid polymer-network gels with rationally designed properties.