A unidirectional carbon fiber-reinforced composite with excellent interlaminar fracture toughness (ILFT) was fabricated, analyzed, and evaluated. The composites were formed by inserting polyethylene-terephthalate (PET)-based thermoplastic veils between prepregs to enhance the ILFT. Carbon nanofiber (CNF)-modified coupling agents were spray-deposited onto the PET veil surface to minimize the reductions in the tensile strength and modulus of the composites caused by the use of thermoplastic veils and maximize the enhancements in the ILFT. The microfibers of the PET veils endowed the composites with delamination resistance, whereas the coupling agents and CNFs coated on the PET surface induced chemical bonding and mechanical interlocking with the epoxy matrix, respectively. Therefore, multiscale reinforcement mechanisms, including these mechanical and chemical interactions, generated a synergistic effect on the mechanical properties of the composites. Reductions in the tensile strength and modulus of the composites decreased by up to 104.7% and 100.8%, respectively, following the application of the CNF/coupling agent-modified PET interleaves, and their Mode-Ⅰ and Mode-Ⅱ ILFT values increased by up to 105.3% and 610.9%, respectively, compared with those of neat composites.

制造、分析和评估了具有优异层间断裂韧性（ILFT）的单向碳纤维增强复合材料。该复合材料是通过在预浸料之间插入基于聚对苯二甲酸乙二醇酯 (PET) 的热塑性面纱来形成的，以增强 ILFT。将碳纳米纤维（CNF）改性偶联剂喷涂到 PET 纱表面上，以最大限度地减少因使用热塑性纱而导致的复合材料拉伸强度和模量的降低，并最大限度地提高 ILFT。PET面纱的微纤维赋予复合材料抗分层性，而涂覆在PET表面上的偶联剂和CNF分别诱导与环氧树脂基体的化学键合和机械联锁。因此，多尺度强化机制，包括这些机械和化学相互作用，对复合材料的机械性能产生协同效应。使用CNF/偶联剂改性PET交织材料后，复合材料的拉伸强度和模量分别降低了104.7%和100.8%，其Mode-Ⅰ和Mode-Ⅱ ILFT值增加了与纯复合材料相比，分别提高到 105.3% 和 610.9%。