1. College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
2. College of Textile Science and Engineering，Donghua University, Shanghai 201620, China
Natural kapok fibers with hollow structures were employed as carbon precursors, and carbonized kapok fibers (CKF) were prepared through a direct carbonization method. These CKF were subsequently utilized as absorbents to fabricate absorbent composites, simultaneously comparing the absorbent performance of composites containing hollow-structured CKF and solidstructured cotton-based carbon fibers as absorbents. It was demonstrated that carbon fibers with hollow morphology enhance electromagnetic wave attenuation. Furthermore, the absorbent properties of composites filled with CKF carbonized at different temperatures under different mass fractions were investigated. When the CKF carbonized at 1000 ℃ was used, and with a 7wt% absorbent addition, composite plates with a thickness of 2 mm exhibited excellent absorbent performance, achieving a minimum reflection loss of -32.7 dB and an effective bandwidth of 5.1 GHz. CKFs not only rely on their solid carbon content for electromagnetic wave absorption through dielectric loss, but also benefit from the abundant interface polarization and interference cancellation induced by their hollow structure, enabling multiple mechanisms for electromagnetic wave attenuation. CKFs show significant potential as absorbents and are poised to play a role in expanding the absorption bandwidth and reducing the weight of absorbent materials.