Asymmetric conductive structure design for stabilized composites with absorption dominated ultra-efficient electromagnetic interference shielding performance

Structurally asymmetric melamine foam (MF)/Polyaniline (Pani)/Fe3O4@reduced graphene oxide (rGO)/Ag-plated aramid paper (AgP)/Polydimethylsiloxane (PDMS) stabilized composites were successfully designed with controlled distribution of the conductive network to accomplish harmonization of electromagnetic absorption and shielding. Wherein, the upper MF/Pani/Fe3O4@rGO/PDMS foam combines in-situ polymerization and dip coating methods utilizing the synergistic effect of conductive Pani and Fe3O4@rGO to achieve superior impedance matching and absorption performance, while the dense conductive network formed in the bottom AgP by electroless plating technique ensures superior electromagnetic shielding effectiveness (EMI SE). With the rational arrangement of the absorptive and conductive shielding layers, MF/Pani/Fe3O4@rGO/AgP/PDMS composites demonstrate of 70 dB and extremely high absorption coefficient (A) of 0.86 at X-band. Notably, benefiting from the asymmetric structural design and PDMS wrapping, the composites possess superior thermal stability, mechanical strength and stable EMI SE. This valid work delivers a useful concept for the rational regulation of conductive networks in shielding composites, improving the applicability in practical environments.