High efficiency microwave absorption and infrared suppression synergistic strategy for 3D Fe₃C/C–SiCN fibers via electrospinning

With the rapid development of electronic technology, electromagnetic pollution and thermal issues are increasingly exacerbating, particularly those enabling microwave-infrared compatibility. However, the integration of electromagnetic protection and thermal management remains a pivotal challenge. This study focuses on the multifunctional compatibility of microwave absorption and infrared stealth, addressing the critical challenge of integrating electromagnetic protection with thermal management for radar-infrared composite detection scenarios. In this work, accompanied by a high-temperature pyrolysis process, three-dimensional conductive network Fe₃C/C-SiCN (3D Fe₃C/C-SiCN) composite fibers with microwave absorption and low infrared emissivity were designed and prepared via the electrospinning technique. The Fe₃C/C-SiCN fibers achieve broadband absorption and low infrared emissivity, an integrated advantage distinguishing them from traditional single-function materials. Microwave absorption and low infrared emissivity by precisely controlling the carbonization temperature, achieving a reflection loss (RL) of −25.11 dB at 1.58 mm, an effective absorption bandwidth (EAB) of 4.72 GHz, and stable long-wave infrared (LWIR) emissivity of 0.51 (at 50 °C) in 8–14 μm with a loading of 30% under a temperature of 700 °C. The synergistic effects of Fe₃C-induced magnetic and interfacial polarization losses, the conductive SiCN-derived carbon network, and the thermally insulating 3D porous structure with low LWIR emissivity result in outstanding multifunctional performance. Fe₃C/C-SiCN composite fibers would hold significant importance in the fields of electromagnetic protection, offering a novel solution for multifunctional electromagnetic protection beyond conventional single-band absorbers.