Robust, flexible, and high-performance electromagnetic interference shielding films with long-lasting service

Abstract

It is of great significance for electromagnetic interference (EMI) shielding materials to fulfill long-lasting service requirements. Here, waterborne polyurethane (WPU) was coated on the surface of a silver nanowire (AgNW) network with sputter-deposited nickel nanoparticles (NiNPs) by dip-coating technology to improve their durability. After five dip-coating cycles, a WPU layer nearly coated the whole surface of the hybrid papers, and only a fraction of the metal filler is bare. The resultant hybrid papers exhibit an electrical conductivity of ∼3500 S m⁻¹, remnant magnetization of 0.03 emu g⁻¹, saturation magnetization of 0.10 emu g⁻¹, and coercivity of 256 Oe. On the one hand, the presence of the WPU coating does not affect the shielding effectiveness (SE) of the hybrid papers; on the other hand, the WPU coating enhances the ability to resist tape peeling. Moreover, the resultant hybrid papers still maintain the original SE value (∼80 dB), even after exposure to air for 5 months owing to the isolation effect of the WPU coating, implying long-lasting durability. The results confirm that the obtained hybrid papers can meet the requirements of practical applications.