Flexible and recoverable SiC nanofiber aerogels for electromagnetic wave absorption

A novel flexible and recoverable SiC nanofiber aerogel (SiC nf aerogel) was synthesized by electrospinning and freeze-drying methods. The SiC fibers prepared by electrospinning technique, have a fine diameter (~600 nm) and excellent flexibility. On this basis, the fibers are stirred at a high-speed and then subjected to freeze-drying and high-temperature treatment to prepare a SiC nf aerogels. The fabricated SiC nf aerogels possess low density (0.039–0.041 g/cm 3 ), excellent thermal insulation (0.025–0.031 W/(m∙K)), and mechanical properties of recoverable strain (~40%). Meanwhile, the SiC nf aerogels show excellent electromagnetic (EM) wave absorption characteristics, which have the effective absorption bandwidth of 9–11.5 GHz (reflection loss (RL) < −10 dB, more than 90% EM wave was absorbed) and minimum RL value attained −21.41 dB at 10.5 GHz with the thickness of 3 mm. The successful preparation of the novel multifunctional material can be used for high temperature insulation materials and electromagnetic wave absorbing materials in harsh environments.