This paper reports on the design and synthesis of tunable electromagnetic (EM) absorbers by encapsulating graphite into SiC nanowires. The hybrid nanowires with controllable dielectric and microwave absorption properties are employed for achieving tunable EM absorbers. The synthesis of the graphite/SiC hybrid nanowires was conducted by electrospinning and high temperature annealing. By simply controlling annealing temperature, the hybrid nanowires annealed at 1300 °C present a maximum reflection loss (RL) of −22 dB at 16.8 GHz with a small thickness of 1.7 mm and an effective absorption bandwidth (RL < −10 dB, 90% EM wave absorption) covers from 8 to 18 GHz. The excellent EM performance is attributed to the dielectric loss which originate from defects of graphite and SiC, interfaces between graphite and SiC, and dangling bond of nanowires surface. This work endows the nanowires potential to be utilized as reinforcements in polymers and ceramics for improving their EM performance with mechanical properties.

本文报道了通过将石墨封装到SiC纳米线中来设计和合成可调谐电磁（EM）吸收器的方法。具有可控的介电和微波吸收特性的混合纳米线被用于实现可调谐的EM吸收器。石墨/ SiC杂化纳米线的合成是通过电纺丝和高温退火进行的。通过简单地控制退火温度，在1300°C退火的杂化纳米线在16.8 GHz处具有-22 dB的最大反射损耗（RL），具有1.7 mm的小厚度和有效的吸收带宽（RL <-10 dB，90％电磁波吸收）覆盖8至18 GHz。优异的EM性能归因于介电损耗，介电损耗源自石墨和SiC的缺陷，石墨与SiC之间的界面，和纳米线表面的悬空键。这项工作赋予了纳米线作为聚合物和陶瓷增强材料的潜力，以改善其具有机械性能的EM性能。