Sánchez-Romate Xoan F, Martin Jesús, Sánchez María, Ureña Alejandro
Materials Science and Engineering Area, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, Calle Tulipán s/n, 28933 Móstoles, Spain.
Nanomaterials (Basel). 2020 Nov 19;10(11):2290. doi: 10.3390/nano10112290.
The fracture behavior and crack sensing of mode-I joints with carbon nanotube (CNT)-reinforced adhesive films were explored in this paper under hydrothermal aging conditions. The measured fracture energy of CNT-reinforced joints in grit blasting conditions is higher for non-aged samples than for neat adhesive joints (around 20%) due to the nanofiller toughening and crack bridging effects. However, in the case of brushed surface-treated adherents, a drastic decrease is observed with the addition of CNTs (around 70%) due to the enhanced tribological properties of the nanofillers. Hydrothermal aging has a greater effect in the CNT-reinforced samples, showing a more prevalent plasticization effect, which is confirmed by the R-curves of the specimens. The effects of surface treatment on the crack propagation properties was observed by electrical resistance monitoring, where brushed samples showed a more unstable electrical response, explained by more unstable crack propagation and reflected by sharp increases of the electrical resistance. Aged specimens showed a very uniform increase of electrical resistance due to slower crack propagation, as induced by the plasticization effect of water. Therefore, the proposed adhesive shows a high applicability for crack detection and propagation without decreasing the mechanical properties.
本文研究了在水热老化条件下，采用碳纳米管（CNT）增强胶膜的I型接头的断裂行为和裂纹传感特性。由于纳米填料的增韧和裂纹桥接效应，在喷砂条件下，未老化的CNT增强接头的测量断裂能高于纯胶粘剂接头（约20%）。然而，对于经过刷涂表面处理的粘附体，由于纳米填料的摩擦学性能增强，添加CNT后观察到断裂能急剧下降（约70%）。水热老化对CNT增强样品的影响更大，表现出更普遍的增塑效应，这通过试样的R曲线得到证实。通过电阻监测观察了表面处理对裂纹扩展特性的影响，其中刷涂样品显示出更不稳定的电响应，这是由更不稳定的裂纹扩展所解释的，并通过电阻的急剧增加反映出来。由于水的增塑效应导致裂纹扩展较慢，老化试样的电阻呈现非常均匀的增加。因此，所提出的胶粘剂在不降低机械性能的情况下，对裂纹检测和扩展具有很高的适用性。
