Synergistic terahertz shielding effects of electrically conductive MXene and shape-controlled magnetic nickel in polyvinylidene fluoride (PVDF) composites

Terahertz (THz) shielding materials have garnered significant attention due to various potential applications in wireless communication, sensing, and defense. In this study, we present efficient THz shielding performance of polyvinylidene fluoride (PVDF) polymer composites incorporated with a mixture of MXene and shape-controlled nickel (Ni) nanoparticles. The PVDF/MXene/Ni composites demonstrated exceptional absorption coefficient and shielding effectiveness against unwanted THz electromagnetic waves, owing to the remarkable synergistic effect between electrically conductive Ti₃C₂T_x MXene and magnetic nickel nanoparticles. Notably, magnetic properties of Ni nanoparticles were controlled by external magnetic field applied during the synthesis process. Flower-like Ni nanoparticles synthesized under an external magnetic field exhibited enhanced magnetic properties compared to spherical Ni nanoparticles synthesized without an external field. As a result, a 20-µm thick PVDF/MXene/Ni composite film, with a 10 wt.% loading of flower-like Ni nanoparticles, demonstrated the THz shielding effectiveness of 34 dB at 1 THz. This shielding performance surpasses those of composite containing spherical Ni nanoparticles (26.7 dB) as well as previously reported shielding materials. These findings highlight an effective approach to tailor the THz shielding properties of polymer composites by modifying the composition and morphology of conductive and magnetic fillers.