（1. Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials, School of Materials Science & Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China）（2. The Third Gas Production Plant of Changqing Oilfield Company, China National Petroleum Corporation, Xi’an 710299, China）
The interphase is an important component of carbon fiber/resin composites, which determines the comprehensive properties of composites. However, since the surface of carbon fiber is chemically inert, it significantly reduces the interfacial adhesion of composites. Therefore, it is an essential breakthrough to improve the interfacial adhesion of composites by surface modification of carbon fiber. In this paper, carbon nanocellulose fibers (CNFs) and carbon nanotubes (CNTs) were introduced onto the surface of circumferential carbon fiber by vacuum filtration, the CNF/CNT/carbon fiber multi-scale reinforcement was introduced to improve the interfacial adhesion of composites. The results showed that the interfacial shear strength of composite with CNF/CNT/carbon fibers increases by 24.1%, which is mainly due to the contribution of enhanced mechanical interlocking between modified fibers and resin and improved fiber surface energy. Vacuum filtration adopted in this work overcomes the prevalent problems that exist in other surface modification methods, such as environmental pollution, complex process, high cost, low efficiency and reduction in fiber tensile strength. Our work reveals a new pathway for tuning fiber surface and improving interfacial properties of composites.