Enhanced mechanical and electromagnetic interference shielding performance of carbon fiber/epoxy composite with intercalation of modified aramid fiber

Inserting aramid fiber (AF) fabric is an effective strategy to improve the impact resistance of carbon fiber reinforced polymer composite (CFRP) when it was used as a material integrated with electromagnetic interference (EMI) shielding and structural functions. Unfortunately, due to the smooth and inert surface of AF, achieving the desirable heterogeneous interface on the surface of AF fabric to simultaneously improve the impact resistance and EMI shielding of CFRP remains a challenge. In this work, a mechanically reinforced carbon fiber (CF)/epoxy composite with efficient EMI shielding effectiveness (SE) was developed via intercalating aramid fiber (AF), which is modified through the "flexible-rigid" structure formed by carbon nanotube (CNT) and polyacrylic acid (PAA). Due to the impressive roughness and wettability of the modified AF, the impact strength of the resultant CF/AF/epoxy composite can reach 80.3 KJ/m 2 , which is 20.6 % higher than that of the composites without modification. Additionally, thanks to the excellent electromagnetic wave loss of "flexible-rigid" heterogeneous interface as well as the unique Jaumann-like structure, the composites also exhibit an efficient EMI shielding effectiveness of 34.4 dB. The desirable impact strength and efficient EMI shielding performance endow the resultant CFRP with a great application potential in electromagnetic protection field.