Construction of rigid‐flexible structure in <scp>MXene</scp>‐Ni‐<scp>CF</scp>/epoxy composite to enhance electromagnetic interference shielding performance and mechanical properties

Abstract With the development of aerospace and modern industry, the demand for carbon fiber reinforced composites (CFRP) with both excellent electromagnetic shielding properties and high mechanical properties became necessary. Herein, a novel modified CFRP with multiscale and hierarchical “rigid‐flexible” nanostructured interphase was constructed by feasible and simple methods. Initially, “flexible” deposited polydopamine (PDA) and “rigid” 2D MXene nanosheets were subsequently introduced on the carbon fiber (CF) surface by dip‐coating method, and then 1D nickel (Ni) chains were further constructed on the surface of modified CF by spray coating approach. At last, the modified CF and epoxy were prepared into related composites (CF‐PDA‐MXene‐Ni/EP) by vacuum‐assisted resin transfer molding (VARTM) method. Results showed that the tensile properties of the modified composite were highly improved compared to those of original CF/EP. The strength and modulus could reach 542.80 MPa and 7.30 GPa, which were respectively 23.59% and 23.94% higher than those of CF/EP. Meanwhile, the tensile failure modes of the composite changed from neat fracture to shear breaking of fiber and yarns. Moreover, the EMI SE of modified composite could reach 68.88 dB, which was improved by 7.07% compared to that of original composite. The innovative design of these kinds of composites offered broad prospects for the next generation of excellent EMI shielding and high mechanical materials. Highlights Polydopamine, 2D MXene, and 1D Ni chains were introduced on carbon fabrics. CF‐PDA‐MXene‐Ni/EP composite was fabricated by the VARTM method. Electromagnetic shielding, as well as tensile behaviors of the composite, were analyzed.