[论文解读] 3D Fluorescent Mapping of Invisible Molecular Damage after Cavi-tation in Hydrogen Exposed Elastomers

Xavier Morelle, Gabriel E. Sanoja+2 more|arXiv (Cornell University)|Jan 3, 2021

Soft Robotics and Applications参考文献 48被引用 35

一句话总结

该论文提出一种非破坏性三维荧光映射方法，用于在氢暴露的弹性体经空化后可视化分子损伤，揭示花状裂纹模式和不连续断裂行为。

ABSTRACT

Elastomers saturated with gas at high pressure suffer from cavity nucleation, inflation, and deflation upon rapid or explosive de-compression. Although this process often results in undetectable changes in appearance, it causes internal damage, hampers func-tionality (e.g., permeability), and shortens lifetime. Here, we tag a model poly(ethyl acrylate) elastomer with {\\pi}-extended anthracene-maleimide adducts that fluoresce upon polymer chain scission, and map in 3D the internal damage present after a cycle of gas satu-ration and rapid decompression. Interestingly, we observe that each cavity observable during the decompression results in a dam-aged region, the shape of which reveals a fracture locus of randomly oriented penny-shape cracks (i.e., with a flower-like morpholo-gy) that contain crack arrest lines. Thus, cavity growth likely proceeds discontinuously (i.e., non-steadily) through the stable and unstable fracture of numerous 2D crack planes. This non-destructive methodology to visualize in 3D molecular damage in polymer networks is novel and serves to understand how fracture occurs under complex 3D loads, predict mechanical aging of pristine look-ing elastomers, and holds potential to optimize cavitation-resistant materials.

研究动机与目标

• 在气体空化后检测弹性体内部损伤的必要性进行动机说明。
• 开发一种非破坏性成像方法，在气体饱和和快速减压后对聚合物网络的三维分子损伤进行映射。
• 理解空化在弹性体中形成断裂的机理和裂纹几何，以预测老化并指导材料设计。

提出的方法

• 用 π-扩展蒽-马来酰亚胺加合物标记聚(乙基丙烯酸酯)弹性体，使其在聚合链断裂时发荧光。
• 进行三维荧光映射以在一次气体饱和和快速减压循环后可视化内部分子损伤。
• 分析损伤的空间模式以推断断裂位置和裂纹几何。
• 将观察到的损伤模式解释为跨越多条随机取向的硬币状裂纹并伴随断裂抑制线的证据。

实验结果

研究问题

• RQ1 三维荧光映射如何揭示在氢暴露弹性体的空化后内部分子损伤？
• RQ2 与空化引起的损伤相关的断裂模式的几何形状与组织是怎样的？
• RQ3 腔体生长是连续进行还是不连续进行，以及裂面如何促成损伤定位？

主要发现

• 在减压过程中观察到的每一个腔体都对应着周围材料中的受损区域。
• 损伤模式形成花状形态，由随机取向的硬币状裂纹及抑制线组成。
• 腔体生长似乎是不连续的，由多个二维裂纹平面的稳定与不稳定断裂驱动。
• 该方法提供一种非破坏性可视化三维分子损伤的方式，并为在复杂三维载荷下的断裂提供见解。