Fe₃O₄‐doped highly electromagnetically shielded PAN‐PVP composite porous carbon films

Abstract With the wide application of modern electronic devices, the problem of electromagnetic pollution is becoming more and more serious, and the demand for efficient electromagnetic shielding materials is becoming more and more urgent. To address this problem, we homogeneously mixed polyacrylonitrile (PAN), polyvinylpyrrolidone (PVP), and triiron tetraoxide (Fe₃O₄) nanoparticles by solution blending, and prepared composite precursor membranes by taking advantage of the magnetic properties and good electromagnetic loss characteristics of Fe₃O₄, as well as the high thermal stability and film‐forming properties of PAN and PVP. Subsequently, carbonized PAN‐PVP/ Fe₃O₄ composite films with different Fe₃O₄ contents were successfully prepared by carbonization under high temperature inert atmosphere to convert PAN and PVP into carbon materials. It was found that the PAN‐PVP/ Fe₃O₄ porous carbon film with 3 wt% Fe₃O₄ addition had a conductivity of 3.99 S·mm⁻¹ at a thickness of 0.42 mm, and an average EMI SE_T of 78.9 dB, SE_A of 64.8 dB, and SSEt of 1838 dB/(cm²·g⁻¹) in the X‐band, which is a typical wave absorbing material and can meet commercial electromagnetic shielding requirements. This work provides new ideas and methods for the research and development of polymer‐based porous carbonized film as electromagnetic shielding materials. Highlights The carbon films with rich porous structure were prepared. Fe₃O₄ was successfully embedded into the carbon film. Carbon films have an efficient conducting network. Carbon film has excellent electromagnetic shielding performance. The main shielding mode of carbon film is absorption.