Structural–Functional Integrated Graphene-Skinned Aramid Fibers for Electromagnetic Interference Shielding

Structural-functional integrated polymer fibers with exciting properties are increasingly important for next-generation technologies. Herein, we report the structural-functional integrated graphene-skinned aramid fiber (GRAF) featuring high conductivity, high strength, and light weight, which is weaved for efficient electromagnetic interference (EMI) shielding. Graphene was self-assembled onto the surface of aramid fibers through a dip-coating strategy using an aramid polyanion (APA) as the binder and the etchant. The molecular dynamics (MD) simulation results show that the binding energy of the APA-modified aramid chain and graphene (1.3 J/m²) is superior to that of the aramid chain and graphene (0.2 J/m²). The APA has a higher surface energy (55.2 mJ/m²) and can etch the fiber surface, forming grooves, which enables effective adsorption and self-assembly of graphene onto the fiber surface. The GRAF exhibits a high conductivity of 1062.04 ± 116.78 S/m, along with excellent strength (4.66 ± 0.16 GPa) and modulus (106.33 ± 8.21 GPa), outperforming most reported conductive composite fibers (e.g., natural fibers, polymer-based fibers, inorganic fibers, etc.). The weaved functional fabric using the structural-functional integrated GRAF shows an EMI shielding efficiency (SE) of up to 67.86 dB in the X-band and can rapidly heat up to 200 °C within 40 s at 12 V voltage. In addition, the GRAF fabric can maintain its electrical conductivity after a long-term washing, showing excellent washing resistance. This study demonstrates an effective method to fabricate structural-functional integrated materials and shows the promise of carbonene fibers for EMI shielding.