In-situ synthesis of Co/Co3O4 nanoparticles decorated carbon nanofiber aerogels for lightweight electromagnetic wave absorption rubber composites with multiple loss effects

Abstract

Carbon-based magnetic absorbents are widely used for electromagnetic wave absorption (EMWA) rubber composites due to the dual electromagnetic wave loss effects of dielectric loss and magnetic loss. Co/Co3O4 nanoparticles decorated carbon nanofiber aerogels (C/Co/Co3O4 aerogels) are prepared by carbonization of nanofiber network structure agarose/cobalt acetate. The in-situ synthetic C/Co/Co3O4 aerogels with carbon nanofiber network structure and controllable particle size of Co/Co3O4 nanoparticles that have the good conductivity and tunable magnetic property increasing both of the dielectric loss and magnetic loss capabilities, which can improve the EMWA performance. Lightweight EMWA rubber composites with 3.75 wt% C/Co/Co3O4 aerogels have the same density as that of silicone rubber (PDMS), the effective absorption band (EAB, frequency for reflection loss<−10 dB) of PDMS/Co-1.25 is aways above 3 GHz when the thickness is bigger than 2.5 mm, the max EAB is 4.24 GHz at the thickness of 2.74 mm. The radar cross section (RCS) reduction can achieve 14 dBm2 when the perfectly electrically conductive (PEC) is covered by a 4.5 mm thick PDMS/Co-1.25. The intensity distributions of electric field, magnetic field and power loss density of EMWA rubber composites are exhibited based on the electromagnetic parameters. The rubber composites based on C/Co/Co3O4 aerogels can be used as lightweight flexible EMWA materials.