Electrospinning of graphite/SiC hybrid nanowires with tunable dielectric and microwave absorption characteristics

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.