弹性体断裂过程中共价键断裂的定量和绘图
Quantifying and mapping covalent bond scission during elastomer fracture
摘要：
最近发现了许多新的柔软但坚韧的橡胶材料，并不断出现新的应用，如柔性假肢，可拉伸电极或软机器人。然而，这些材料的损伤和断裂的可靠的多尺度定量图片仍然没有出现，由于我们根本无法解开沿着断裂路径的化学键的不可逆断裂从内部分子摩擦耗散。在这里，通过耦合新的荧光力学化学与定量共聚焦显微镜映射，我们发现有多少和在哪里共价键被打破的弹性体断裂。我们的测量结果表明，键断裂附近的裂纹平面可以离域超过数百微米，并增加了100倍，这取决于温度和拉伸速率，指向一个复杂的耦合应变速率依赖的粘性耗散和应变依赖的不可逆网络断裂。这些发现描绘了一幅全新的软材料断裂图景，其中共价键断裂耗散的能量占总断裂能的比例比以前认为的要大得多。我们的研究结果开创了灵敏，定量和空间分辨检测键断裂，以评估各种软材料及其应用中的材料损伤。
英文摘要：
Many new soft but tough rubbery materials have been recently discovered and new applications such as flexible prosthetics, stretchable electrodes or soft robotics continuously emerge. Yet, a credible multi-scale quantitative picture of damage and fracture of these materials has still not emerged, due to our fundamental inability to disentangle the irreversible scission of chemical bonds along the fracture path from dissipation by internal molecular friction. Here, by coupling new fluorogenic mechanochemistry with quantitative confocal microscopy mapping, we uncover how many and where covalent bonds are broken as an elastomer fractures. Our measurements reveal that bond scission near the crack plane can be delocalized over up to hundreds of micrometers and increase by a factor of 100 depending on temperature and stretch rate, pointing to an intricated coupling between strain rate dependent viscous dissipation and strain dependent irreversible network scission. These findings paint an entirely novel picture of fracture in soft materials, where energy dissipated by covalent bond scission accounts for a much larger fraction of the total fracture energy than previously believed. Our results pioneer the sensitive, quantitative and spatially-resolved detection of bond scission to assess material damage in a variety of soft materials and their applications.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
