Construction of an Orderly Carbon Fiber/Carbon Nanotubes Hybrid Composites by a Mild, Effective, and Green Method for Highly Interface Reinforcement

The low‐damage and high‐efficiency tight bonding of two inert materials, carbon nanotubes (CNTs) and carbon fibers (CFs), is implemented simply and mildly based on the secondary reaction platform role of polydopamine (PDA). The strong adhesion of PDA can fix varying masses of CNTs stably and uniformly on the surface of carbon fiber, which significantly augments the polar component and roughness of fiber surface. In the proposed control method, the interface shear strength and interlaminar shear strength of CF‐PDA6‐CNTs0.05 increase by ≈61.03% and 55.30% compared to desized CFs based composites. Remarkably, the improvement mechanism in the mechanical properties of the composites is analyzed by the transverse fracture morphology of the composites as well as thermodynamically. By copolymerizing carbon nanotubes (CNTs) and polydopamine (PDA) in a simple and mild form, the CNTs are enabled to be uniformly distributed and successfully applied to modify the surface of carbon fiber without injury. The effects of PDA/CNTS coating on carbon fiber and their composites are systematically investigated. The enhancement mechanism of the interfacial properties of composites is investigated from several perspectives.