Abstract This paper focuses on improving the out-of-plane properties of carbon fiber/epoxy composites to extend their applications. Carbon nanotubes (CNTs) were introduced on carbon fiber surface by a novel one-step chemical vapor deposition (CVD) method at ultra-low temperature and hybrid composites were fabricated by molding technology. Mechanical and dielectric tests were conducted to figure out the changes in out-of-plane properties after grafting CNTs. The results of single-fiber tensile strength indicated that both the strength and the Weibull modulus of the CNTs-coated carbon fiber increased due to the less damage caused to the fiber by catalysts at low temperature and the repairing effect of the CNTs. Compared with the properties of desized fiber based composites, both interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) of CNTs-coated fiber/epoxy composites increased by 30.73% and 32.29%, respectively, as well as the dielectric properties were also improved. The fracture mechanisms of CNTs were investigated based on the morphology observation on the interface. The improved out-of-plane properties were associated with the improved stress transfer between the carbon fibers and surrounding matrix through the newly formed interphase induced by CNT layer.

中文翻译：

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使用一步法在超低温下将碳纳米管接枝到纤维上改善碳纤维/环氧树脂复合材料的界面

摘要 本文着眼于提高碳纤维/环氧树脂复合材料的面外性能以扩展其应用。通过一种新型的一步化学气相沉积（CVD）方法在超低温下将碳纳米管（CNT）引入碳纤维表面，并通过成型技术制造混合复合材料。进行机械和介电测试以找出接枝 CNT 后面外特性的变化。单纤维拉伸强度结果表明，由于催化剂在低温下对纤维的损伤较小以及CNTs的修复作用，CNTs包覆的碳纤维的强度和威布尔模量均有所提高。与退浆纤维基复合材料的性能相比，CNTs包覆的纤维/环氧树脂复合材料的界面剪切强度（IFSS）和层间剪切强度（ILSS）分别提高了30.73%和32.29%，介电性能也得到了改善。基于界面形貌观察研究了碳纳米管的断裂机制。改进的面外特性与通过由 CNT 层引起的新形成的中间相在碳纤维和周围基体之间改进的应力传递有关。