Double-layer of CNF/rGO film and CNF/rGO/FeCo-LDO aerogel structured composites for efficient electromagnetic interference shielding

Electromagnetic radiation seriously affects the normal use of electronic components, and secondary electromagnetic pollution may even harm people's health. Developing electromagnetic shielding materials with high electromagnetic wave absorption capacity is of great significance in reducing secondary reflection of electromagnetic wave. In this paper, CNF/rGO composite film and CNF/rGO/FeCo-LDO aerogel were combined to prepare a double-layer structured electromagnetic shielding composite. The magnetic porous aerogel and conductive composite film can be used as the absorption layer and reflection layer of electromagnetic wave respectively, which can effectively improve the total electromagnetic shielding efficiency and absorption coefficient (A) of the structured composite materials. The composite film (0.8 mm) produces an electromagnetic shielding effect of up to 65 dB, under the combined action of the absorption-reflection-reabsorption process of the porous structure of the aerogel (5.0 mm) and the magnetic loss of the magnetic particle FeCo-LDO, the electromagnetic wave absorption coefficient (A) reaches 0.68. The effects of the films' thickness, the solid content of the aerogel, and the compression ratio of the aerogel on the electromagnetic shielding performance were also discussed. The total electromagnetic shielding efficiency increases with the increase of film thickness, and the An increases with the increase of the solid content of aerogel. This work provides a simple method to prepare an electromagnetic shielding composite with high shielding performance and absorption efficiency through constructing a film-aerogel double-layer structure.