Two-layer structural method: An efficient strategy inspired by machine learning for nanocomposites with magnetic particles for electromagnetic interference shielding

Nowadays, preparing efficient electromagnetic interference shielding materials has been a significant issue for decades. In composites for Electromagnetic Interference (EMI) shielding, combing electrically conductive particles and magnetic loss particles is a general method to enhance the absorption of electromagnetic waves (EMW) and the entire EMI shielding performance. According to our preview work of machine learning to optimize nanocomposite for EMI shielding, the particle loading is much more significant than the thickness of the composites, which inspires a potential way to improve particle utilization. Therefore, we propose a new two-layer structural composite concept for a composite containing magnetic particles for EMI shielding: for a composite with the same amount of CNT and CIP and the same thickness, instead of mixing them in a composite but separating them into two layers. This work uses powder sintering to prepare the two-layer and blended composites with the same materials and thicknesses. The results demonstrate that the two-layer structure maintains much better total shielding effectiveness. Besides, the electrothermal conversion results also show the superiority of this structure, hinting at the potential of this structure to realize the sustainability of other functional composites.