Synthesis of SiC nanofibers with superior electromagnetic wave absorption performance by electrospinning

A method combined electrospinning and preceramic polymer pyrolysis, annealing has been developed to fabricate SiC nanofibers. In this work, the effects of polycarbosilane (PCS) mass ratio (8.7 wt% ∼ 11.8 wt%) in precursor solution on microstructure and electromagnetic (EM) absorption properties of SiC nanofibers are systematically studied. The phase composition of SiC nanofibers are mainly inclusive of abundant SiC nanocrystallines, a small quantity of graphitic-like carbon coated on fibers surface and randomly distributed amorphous SiOxCy phase. When PCS mass ratio is 10 wt%, the SiC nanofibers present a minimum reflection loss (RL) value of −57.8 dB at 14.6 GHz with a absorber coating thickness of 1.9 mm and the effective absorption bandwidth (RL < −10 dB, 90% EM wave absorbed) covers from 6 to 18 GHz. As PCS mass ratio increasing, the EM absorption performance of SiC nanofibers gradually becomes poor. Multi-reflection among SiC nanofibers gradually weaken the incident EM wave. Moreover the interfacial polarization originated from heterogeneous interfaces which exist among SiC nanocrystallines, graphite carbon, amorphous SiOxCy dissipates EM wave energy contributed to high EM performance of SiC nanofibers. This work demonstrates a new kind of nano SiC EM absorption materials that has potential to be applicated in harsh environments.