Piezoresistive structural composites reinforced by carbon nanotube-grafted quartz fibres
Piezoresistive structural composites reinforced by carbon nanotube-grafted quartz fibres
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DOI：
10.1016/j.compscitech.2020.108275
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发表时间：
2020-09
影响因子：
9.1
通讯作者：
H. D. Luca;D. B. Anthony;E. Greenhalgh;A. Bismarck;M. Shaffer
中科院分区：
文献类型：
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作者：
H. D. Luca;D. B. Anthony;E. Greenhalgh;A. Bismarck;M. Shaffer
纳米工程纤维/基体界面可以改进最先进的纤维增强复合材料。将碳纳米管（CNT）接枝到高温石英玻璃纤维上可产生“毛状”或“毛状”纤维，这种纤维结合了微米和纳米长度尺度的增强材料。在开放式化学气相沉积反应器中，以整束卷对卷的方式连续生产模糊石英纤维。通过单纤维拉拔测试测得，与商业尺寸的对应物相比，200 nm 长 CNT 的均匀覆盖使环氧树脂界面剪切强度 (90.3 ± 2.1 MPa) 提高了 12%。使用单向分级束复合材料在宏观尺度上证实了界面性能的改善，该复合材料表现出纤维/基体脱粘的延迟发生。尽管石英纤维是电绝缘的，但接枝的碳纳米管会形成一条导电路径，主要与纤维平行。为了探索结构健康监测的适用性，在机械测试中现场记录电阻率，并与同步声发射数据相关联。平行于纤维的基线电阻率 (ρ0= 3.9 ± 0.4 × 10−1Ω m) 显示出线性压阻响应 (K = 3.64)，直到大约失效。 2.1% 应变，也称为“应变系数”，比传统电阻应变计（例如康铜）提高两倍。因此，分层模糊石英纤维可同时增强结构和传感性能，为大型复合材料零件提供多功能机会。
Nano-engineered fibre/matrix interfaces can improve state-of-the-art fibre-reinforced composites. Grafting carbon nanotubes (CNTs) to high temperature quartz glass fibres produces “hairy” or “fuzzy” fibres, which combine reinforcements at micrometre and nanometre length scales. Fuzzy quartz fibres were produced continuously, reel-to-reel, on whole tows, in an open chemical vapour deposition reactor. The resulting uniform coverage of 200 nm long CNTs increased the interfacial shear strength with epoxy (90.3 ± 2.1 MPa) by 12% compared to the commercially-sized counterpart, as measured by single fibre pull-out tests. The improved interfacial properties were confirmed at the macroscale using unidirectional hierarchical bundle composites, which exhibited a delayed onset of fibre/matrix debonding. Although the quartz fibres are electrically insulating, the grafted CNT create a conductive path, predominantly parallel to the fibres. To explore the applicability for structural health monitoring, the resistivity was recordedin situduring mechanical testing, and correlated with simultaneous acoustic emission data. The baseline resistivity parallel to the fibres (ρ0= 3.9 ± 0.4 × 10−1Ω m) displayed a linear piezoresistive response (K = 3.64) until failure at ca. 2.1% strain, also referred to as "gauge factor”, a two-fold improvement over traditional resistance strain gauges (e.g. constantan). Hierarchical, fuzzy quartz fibres, therefore, simultaneously enhance both structural and sensing performance, offering multifunctional opportunities in large composite parts.