Three‐Dimensional Interfacial Engineering of Carbon Fibers for Enhanced Mechanical Properties and Electromagnetic Shielding of Carbon Fiber Composites

ABSTRACT In this study, a green and facile layer‐by‐layer self‐assembly strategy was developed to construct a robust and functionalized interfacial layer on carbon fiber (CF) surfaces. Three‐dimensional reduced graphene oxide (rGO), polydopamine (PDA), and tamarind seed polysaccharide (TSP) were sequentially deposited onto the CF surface. The synergistic effects of the three components significantly enhanced both the mechanical and electrical properties of the resulting carbon fiber‐reinforced polymers (CFRPs). Compared with pristine CF/EP composites, the modified CFRPs exhibited increases of 59.5%, 51.7%, and 54.2% in flexural strength, flexural modulus, and interlaminar shear strength (ILSS), respectively. Furthermore, the electrical conductivity increased markedly from 1.5 to 10.7 S/cm. More importantly, the enhanced conductive network and three‐dimensional architecture significantly improved the electromagnetic shielding effectiveness (SE), reaching 30.95 dB, 56.2% higher than that of the unmodified composite. This work not only provides a green and efficient approach for carbon fiber interfacial engineering but also offers novel design insights for developing multifunctional CFRPs with both high mechanical strength and excellent electromagnetic shielding performance.