Compressive failure of hydrogel spheres
Compressive failure of hydrogel spheres
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DOI：
10.1557/jmr.2020.114
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发表时间：
2020-05-28
影响因子：
2.7
通讯作者：
Oyen, Michelle L.
中科院分区：
文献类型：
--
作者：
James, Jeremiah D.;Ludwick, Jacoh M.;Oyen, Michelle L.
水凝胶由于其大的水含量而获得了最近的生物医学应用的关注，这赋予了生物相容性。然而，它们的机械性能可能是有限的。最近，除了水凝胶材料的刚度和时间依赖性行为之外，还对水凝胶材料的强度和断裂韧性产生了显著的兴趣。水凝胶可以以脆性的方式失效，尽管它们非常柔顺。在这项工作中，使用球形水凝胶颗粒的压缩测试来检查水凝胶的失效和断裂。将市售聚丙烯酰胺-聚丙烯酸钾的球体水合并测试其在压缩中作为加载速率的函数的失效。当压缩到小的固定位移时，球体几乎没有松弛。所获得的强度值的分布进行了检查，在颗粒断裂框架以前用于脆性陶瓷。有加载速率依赖性明显在测得的峰值力和计算的峰值强度值，但数据下降的水凝胶的强度的一个单一的经验分布函数，无论加载速率。这些水凝胶的强度值大多在0.05- 0.3MPa的范围内，说明了使用水凝胶用于机械要求高的应用如组织工程的挑战。
Hydrogels have gained recent attention for biomedical applications because of their large water content, which imparts biocompatibility. However, their mechanical properties can be limiting. There has been significant recent interest in the strength and fracture toughness of hydrogel materials in addition to their stiffness and time-dependent behavior. Hydrogels can fail in a brittle manner, although they are extremely compliant. In this work, the failure and fracture of hydrogels are examined using a compression test of spherical hydrogel particles. Spheres of commercially available polyacrylamide-potassium polyacrylate were hydrated and tested to failure in compression as a function of loading rate. The spheres exhibited little relaxation when compressed to small fixed displacements. The distributions of strength values obtained were examined in a particle fracture framework previously used for brittle ceramics. There was loading rate dependence apparent in the measured peak force and calculated peak strength values, but the data fell on a single empirical distribution function of strength for the hydrogels regardless of loading rate. Strength values for these hydrogels were mostly in the range of 0.05-0.3 MPa, illustrating the challenges using hydrogels for mechanically demanding applications such as tissue engineering.