Flexible PEDOT:PSS/PVA/Co3O4 nanocomposite films with absorption-dominated EMI shielding performance

Abstract

The increasing reliance on high-frequency electronics has intensified the need for lightweight and efficient electromagnetic interference (EMI) shielding materials. In this work, PEDOT:PSS/PVA/Co₃O₄ nanocomposite films were developed using a conductive polymer–metal oxide composite design strategy to overcome the limited conductivity and weak attenuation mechanisms of conventional polymer shields. By varying the Co₃O₄ content from 0 to 40 wt%, a clear correlation was established between the structure and properties, linking the nanoparticle dispersion with the high-frequency electromagnetic response. Structural, morphological, elemental, mechanical, and electrical analyses collectively demonstrate the effective dispersion of Co₃O₄ nanoparticles within the conductive PEDOT:PSS/PVA matrix. EMI analyses reveal that absorption-related attenuation dominates over reflection due to the combined effects of conductive loss, interfacial polarization, and multiple scattering. The EMI shielding effectiveness across the X, Ku, and K bands confirms that the high shielding performance of the optimal sample is attributed to its proximity to the optimal dispersion state and uniform filler distribution. These findings highlight a rationally engineered, flexible, and lightweight nanocomposite with strong potential for next-generation communication, aerospace, and wearable electronic systems.