Engineering a chitosan-based interwoven network on carbon fibers for synergistically enhanced mechanical properties and EMI shielding performance of composites

Abstract

Carbon fiber-reinforced polymer composites (CFRPs) have been widely utilized in aerospace, transportation, and electronic engineering owing to their high specific strength, stiffness, and lightweight nature. However, achieving simultaneous enhancement of mechanical performance, environmental durability, and electromagnetic interference (EMI) shielding remains a significant challenge. In this study, a green and sustainable interfacial modification strategy was developed by constructing a bio-inspired interwoven architecture consisting of chitosan (CS), metal–phenolic networks (MPN), and carbon nanotubes (CNTs) on the carbon fiber surface. The resulting hierarchical structure increased surface roughness and introduced abundant functional groups, thereby strengthening fiber–matrix interfacial interactions and facilitating stress transfer. The introduction of the engineered interphase led to pronounced enhancements in composite mechanical properties. The optimal formulation achieved increases of 41.7% in interlaminar shear strength, 45.3% in flexural strength, and 55.5% in transverse fiber bundle tensile strength relative to the untreated counterpart. Furthermore, the engineered interface effectively preserved interfacial integrity during thermal aging, leading to enhanced durability. Benefiting from the interconnected conductive network and abundant interfacial polarization sites, the modified composites exhibited improved electromagnetic wave attenuation through conductive loss, polarization loss, and multiple scattering/reflection mechanisms, resulting in superior EMI shielding performance. This work provides an environmentally friendly and scalable approach for multifunctional interface engineering of CFRPs and demonstrates considerable potential for advanced structural and functional applications.