Yao Xudan, Hui Jason H, Kinloch Ian A, Bissett Mark A
Department of Materials, Henry Royce Institute, National Graphene Institute, University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
ACS Appl Eng Mater. 2024 Jul 8;2(7):1836-1844. doi: 10.1021/acsaenm.4c00236. eCollection 2024 Jul 26.
Despite their excellent mechanical performance, carbon fiber-reinforced polymer (CFRP) composites are limited by the interfacial properties due to the inherent nature of laminated structures. One way to modify the interface is by the inclusion of nanomaterials. Here, we use electrochemical exfoliation to produce graphene (EEG) flakes that have hydroxyl and epoxy functional groups. To further improve the interfacial bonding, silanization was carried out on graphene with 3-aminopropyl triethoxysilane, and then, EEA flakes were achieved. Both flakes were dispersed in ethanol and spray-coated onto carbon fibers, followed by vacuum-assisted resin infusion to make hybrid composites. Testing of their mechanical properties showed that EEG flakes tend to act as points of stress concentration, which accelerated the delamination, while the EEA flakes improved interfacial properties owing to the covalent bonding. As a result, with only 0.5 wt % EEA flakes spray-coated onto the carbon fibers, the tensile and flexural strength of graphene/carbon fiber composites improved by 17.6 and 5.4%, respectively. The combination of electrochemical exfoliation, silanization, spray coating, and vacuum-assisted resin infusion enables large-scale hybrid composite fabrication without size or shape limitations, without weakening the CFs or carbon fabric patterns, and is suitable for continuous production. This process has proven to be practical and attractive for engineering applications.
尽管碳纤维增强聚合物（CFRP）复合材料具有优异的机械性能，但由于层压结构的固有特性，其界面性能受到限制。一种改善界面的方法是加入纳米材料。在此，我们采用电化学剥离法制备了具有羟基和环氧官能团的石墨烯（EEG）薄片。为了进一步改善界面结合，用3-氨丙基三乙氧基硅烷对石墨烯进行硅烷化处理，从而得到EEA薄片。将两种薄片都分散在乙醇中，然后喷涂到碳纤维上，接着通过真空辅助树脂灌注制备混杂复合材料。对其机械性能的测试表明，EEG薄片倾向于成为应力集中点，加速了分层，而EEA薄片由于共价键作用改善了界面性能。结果，仅在碳纤维上喷涂0.5 wt%的EEA薄片，石墨烯/碳纤维复合材料的拉伸强度和弯曲强度分别提高了17.6%和5.4%。电化学剥离、硅烷化、喷涂和真空辅助树脂灌注相结合，能够大规模制造混杂复合材料，不受尺寸或形状限制，不会削弱碳纤维或碳纤维织物的图案，且适合连续生产。这一工艺已被证明在工程应用中具有实用性和吸引力。
