Multifunctional heterostructured composite foam with 3D hierarchical network for efficient electromagnetic interference shielding

Abstract

The development of multifunctional electromagnetic interference (EMI) shielding materials represents an important research direction. However, the challenge remains to develop multifunctional and high-performance electromagnetic waves (EMW) shielding materials through the effective integration of multiple functions into the materials through appropriate multicomponent strategies and ingenious microstructural design. In this study, magnetic Fe3O4 nanoparticles with polypyrrole (PPy) encapsulation were successfully assembled on melamine foam (MF) with a hierarchical structure combined with a highly conductive silver layer by in situ polymerization and cyclic immersion processes to achieve absorption-dominated electromagnetic shielding and multifunctionality. The composite benefits from good impedance matching, dielectric/magnetic losses, interfacial/dipole polarization, and internal multiple reflections and scattering due to the three-dimensional conductive network. Moreover, the high concentration of modified Fe3O4@PPy particles assembled on the MF skeleton ensures that the multifunctional heterostructured composite foams remain stable and superhydrophobic even when the surface is repeatedly abraded. At the same time, MHCF exhibits excellent thermal insulation and infrared stealth properties. This work offers new insights into the design and development of lightweight and multifunctional high-performance EMW shielding materials, while simultaneously opening up new prospects for their practical applications.