Spiral engineering for carbon fibers wrapped with CoNi nanoparticle showing great potential in multiband absorption, aerogelation and self‐cleaning

Abstract Although carbon fiber electromagnetic wave absorbing materials have shown great potential in the field of electromagnetic protection, the currently reported carbon fiber‐based absorbers are limited to the manipulation of composition and external structure, lacking the design of intrinsic morphology. To fill the above‐mentioned gap, this work presents a spiral carbon fiber compounded with CoNi magnetic nanoparticles (CoNi@SCF). Attributed to its special morphology and dielectric‐magnetic synergy, this material offers abundant attenuation mechanisms, demonstrating strong absorption at multiple frequencies with broadband application potential. In particular, the maximum reflection loss and effective absorption bandwidth of CoNi@SCF reach −66.5 dB at 2.9 mm and 6.6 GHz at 2.1 mm, respectively, and the maximum RCS reduction value of 41.5 dB m 2 also confirms the actual efficiency. In addition, gelation and hydrophobic modification experiments have been explored to meet the requirements for the employment of magnetic carbon fibers in practical scenarios. Therefore, this work may provide new inspiration for the design and manufacture of novel magnetic carbon fiber absorbers with great stability and multiband absorption performance.