Enhanced Electromagnetic Wave Absorption of Carbon Fiber Composites Coated with Nickel Nanoparticles: Structural Design, Characterization, and Mechanism Analysis

Abstract

Carbon fiber (CF), often referred to as “black gold”, is renowned for its exceptional properties of corrosion resistance, low density, high modulus, and lack of creep. However, the poor impedance matching of CF hinders the enhancement of its effective absorption bandwidth (EAB). In additional, the single loss mechanism results in the peak electromagnetic wave (EMW) reflection loss (RL) of CF occurring at high frequencies (>12 GHz). To address these issues, we propose a compositional and structural design of CF with magnetic particles and employ first-principles calculations to reveal the charge transfer processes within the CF and Ni structures during relaxation. The resulting CF@Ni-6 exhibits an RLmin of −49.87 dB at 15.92 GHz and an EABmax of 5.92 GHz (12.08 −18.00 GHz) with a thickness of 2.2 mm, covering almost the entire Ku band. By adjusting the amount of Ni particles, the minimum reflection loss (RLmin) of CF@Ni-9 reaches −52.29 dB at 4.8 GHz with a thickness of 4.6 mm. The successful preparation of CF uniformly coated with nickel particles achieves Ku-band coverage and high RL, providing new insights into the design and fabrication of EMW absorbing materials.

Keywords: carbon fiber, impedance matching, Dielectric-magnetic synergy, electromagnetic wave absorption