Multispectral electromagnetic shielding using ultra-thin metal-metal oxide decorated hybrid nanofiber membranes

Abstract

Lightweight shielding materials that can protect devices against undesirable multispectral electromagnetic waves are critical in electronic, medical, military, and aerospace applications. However, the existing shielding materials are heavyweight and work only in a narrow frequency-range. In this work, we developed metal–metal oxide Ag-WO3 decorated polymeric nanofiber hybrid membranes with versatile multispectral electromagnetic shielding abilities for practical applications. The Ag-WO3 hybrid provides multiple functions, such as excellent metallic conductivity provided by silver, high photoelectric effect and low thermal conductivity arising from the high atomic number in WO3, and strong infrared energy absorbing capability caused by a designed Schottky barrier interface between Ag and WO3. Additionally, the nanofibrous hybrid membrane structure provides high surface area, good air permeability, and robust mechanical strength and durability. These highly conductive, lightweight, ultrathin, and flexible membranes exhibit efficient microwave electromagnetic interference shielding of 92.3 dB at a thickness of ~42 μm in 8–26.5 GHz frequency range, 0.75–0.5 emissivity for near- to far-field infrared bands, and 32.03% attenuation for X-rays of 30 keV at 0.24 mm thickness, indicating their potential for shielding against large-scale multispectral electromagnetic waves from low-frequency microwaves to high-frequency X-rays.