Flexible ANF-based Janus films incorporating SiCnw@rGO networks for absorption-enhanced EMI shielding and efficient thermal management

With the rapid development of high-power electronic devices, there is an urgent need for materials that can simultaneously shield electromagnetic radiation and conduct thermal management. However, traditional materials usually have problems of single function and excessive reflection of electromagnetic waves, which will easily cause secondary environmental pollution. In order to cope with these challenges, this study proposes a simple and effective method to prepare an asymmetric ANF/Fe 3 O 4 @BNNS-SiCnw@rGO (AFBSG) Janus composite film by vacuum-assisted filtration. The upper layer of the film integrates Fe 3 O 4 nanoparticles and insulating nanosheets BNNS (Fe 3 O 4 @BNNS) into the ANF matrix (AFB), allowing electromagnetic waves to enter and dissipate through magnetic loss while reducing surface reflection. The lower layer is composed of rGO and SiCnw (SiCnw@rGO) with high conductive network integrated into the ANF matrix (ASG), providing strong conductivity and promoting multiple reflections of electromagnetic waves inside the material. This double-layer Janus structure achieves an efficient “absorption-reflection-reabsorption” mechanism inside the material. The results show that the AFBSG composite film not only exhibits excellent electromagnetic shielding efficiency of 40 dB, but also significantly improves the absorption capacity of electromagnetic shielding (A coefficient of 0.26). In addition, the film delivers a combination of superior heat dissipation, thermal stability at 500°C, a tensile strength of 87.17 MPa, and remarkable flexibility.