Facile synthesis of ultra-lightweight silver/reduced graphene oxide (rGO) coated carbonized-melamine foams with high electromagnetic interference shielding effectiveness and high absorption coefficient

Abstract Endowing electromagnetic interference (EMI) shielding foams with ultralow density and dynamic stable structure is crucial yet challenging. Here, we propose a facile one-step thermal treatment strategy to fabricate lightweight silver/reduced graphene oxide-coated carbonized melamine (CMF/rGO/Ag) hybrid foams with remarkable mechanical performance and outstanding EMI shielding effectiveness (EMI SE). Due to interfacial reinforcement of rGO between CMF skeleton and silver, the CMF/rGO/Ag foams show outstanding structural stability after 1000 cycles of a loading-unloading compression test. Moreover, The EMI SE of the foams reaches 50.6 dB at a mere density of 16 mg cm−3. The normalized surface-specific SE is up to 7616 dB cm2 g−1 with an ultralow Ag content of 0.09 vol%. Interestingly, the collaboration of the porous skeleton and multiple interfaces contribute to an anomalous high absorption coefficient of CMF/rGO/Ag foams (over 0.5). The high-absorption-coefficient shielding mechanism of the CMF/rGO/Ag foams was further studied by finite element analysis (FEA). The remarkable near-field EMI shielding performance of the CMF/rGO/Ag foam demonstrates that the low density and robust CMF/rGO/Ag foam have enormous advantages and wide application prospects as EMI shielding materials of electronic packaging.