Robust and flexible silver-embedded elastomeric polymer/carbon black foams with outstanding electromagnetic interference shielding performance

Designing robust, flexible, and low metal consuming hybrid foams for high-performance electromagnetic interference (EMI) shielding is crucial yet challenging. A new metallization strategy of foam type materials is presented to fabricate the robust and flexible silver embedded poly (styrene-block-butadiene-block-styrene)/carbon black hybrid foam (Ag@SBS/CB) with ultra-low silver consumption. The synergistic effect between the embedded isolate Ag nanoparticles and carbon black endows the Ag@SBS/CB foam with high mechanical and electrical stability as well as outstanding EMI shielding performance. The Ag@SBS/CB foam can endure over 1500 cycles of the compression-release test without detectable decay in the relative conductivity. A significant influence of the pore size and the silver fraction on the EMI shielding performance is revealed, providing an intriguing microstructure design strategy. The EMI shielding effectiveness (SE) of the foam reaches 81.3 dB with the silver fraction of 0.63 vol% and a CB fraction of 15 wt% at a thickness of about 5 mm. In particular, the Ag@SBS/CB foam with a thinner thickness of 2 mm shows a much better near-field EMI shielding than Al plate.