Lightweight and hydrophobic Ni/GO/PVA composite aerogels for ultrahigh performance electromagnetic interference shielding

Abstract

Lightweight and high-performance electromagnetic interference (EMI) shielding materials are urgently required to solve increasingly serious radiation pollution. However, traditional lightweight EMI shielding materials usually show low EMI shielding performance, poor mechanical properties, and environmental stability, which greatly limit their practical applications. Herein Ni foam/graphene oxide/polyvinyl alcohol (Ni/GO/PVA) composite aerogels were successfully prepared by a freeze-drying method. The Ni/GO/PVA composite aerogels possessed low density (189 mg cm-3) and high compression strength (172.2 kPa) and modulus (5.5 MPa). The Ni/GO/PVA composite aerogel was hydrophobic, and their contact angle can reach 145.2°. The hydrophobic modification improved the environmental stability of the composite aerogels. Moreover, the Ni/GO/PVA composite aerogels exhibited excellent EMI shielding performance. Their maximum EMI shielding effectiveness (SE) can reach 87 dB at the thickness of 2.0 mm. When the thickness is only 1.0 mm, the EMI SE can still reach 60 dB. The electromagnetic energy absorption and attenuation mechanisms of Ni/GO/PVA composite aerogels include multiple reflection and scattering, dielectric loss, and magnetic loss. This work provides a promising approach for the design and preparation of the lightweight EMI shielding materials with superior EMI SE, which may be applied in various fields such as aircrafts, spacecrafts, drones, and robotics.