Abstract Carbon fiber inevitably generates a large number of defects coupling with the multi-functional groups on its surface during the production process. As a result, these defects will cause stress concentration at the interface, thereby reducing the performance of carbon fiber reinforced polymer composites (CFRPs). In this work, a self-driven method is adopted to repair the surface defects of CFs to improve the interface properties of CFRPs. The surface of CFs is sized by nano-carboxymethyl cellulose (CMC) with multi-functional groups. Due to the existence of multi-functional groups on the surface defects of CFs and the non-polarity of other areas in CFs, CMC can automatically gather at the defects via polar attraction between the multi-functional groups to achieve the self-driven repair. Besides, due to the film-forming properties of CMC, the surface defects will be used as a fixed points to form a tight layer of nanofiber membrane with the multi-functional groups on the surface of CFs. It is found that the repair of CFs surface defects and the introduction of multi-functional groups will synergistically enhance the interface performance of epoxy-based composite. The modification method is environmental benign, which lays a research foundation for improving the interface properties of CFRPs using natural cellulose.

中文翻译：

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羧甲基纤维素施胶修复环氧复合材料中的碳纤维表面缺陷

摘要 碳纤维在生产过程中不可避免地会产生大量与其表面的多功能基团耦合的缺陷。结果，这些缺陷会导致界面处的应力集中，从而降低碳纤维增强聚合物复合材料（CFRPs）的性能。在这项工作中，采用自驱动方法修复 CFs 的表面缺陷，以改善 CFRPs 的界面性能。CFs的表面由具有多功能基团的纳米羧甲基纤维素（CMC）调整大小。由于CFs表面缺陷上存在多功能基团，而CFs中其他区域的非极性，CMC可以通过多功能基团之间的极性吸引力自动聚集在缺陷处，实现自驱动修复。此外，由于 CMC 的成膜性，表面缺陷将作为固定点与CFs表面的多功能基团形成紧密的纳米纤维膜层。发现CFs表面缺陷的修复和多功能基团的引入将协同增强环氧基复合材料的界面性能。该改性方法对环境无害，为利用天然纤维素改善CFRPs的界面性能奠定了研究基础。