Microcellular Carbon\nNanotube/Thermoplastic Elastomer\nNanocomposite Foam to Amplify Absorption-Driven Electromagnetic Shielding\nEfficiency

The increasing proliferation of electronic devices has\nled to significant\nelectromagnetic pollution, posing risks to communication systems and\nhuman health. Moreover, the trend toward miniaturizing electronic\ncomponents complicates effective heat dissipation, leading to overheating\nand degraded performance. To address these issues, a microcellular\nnanocomposite foam composed of ethylene–octene copolymer (EOC)\nand multiwall carbon nanotubes (MWCNTs) was developed by using a blend\nof melt and solution mixing techniques. A chemical blowing agent was\nemployed to introduce porous structures into the nanocomposite, resulting\nin a foam with a density range of 0.4–0.53 g/cm<sup>3</sup> and a low percolation threshold at 4 wt %. This porous composite\ndemonstrated an outstanding electromagnetic interference (EMI) shielding\neffectiveness of 25.5 dB in a 2 mm thick, 10 wt % MWCNT-loaded nanocomposite\nwithin the X-band frequency. Additionally, the composite foam exhibited\na thermal conductivity of 0.25 Wm<sup>–1</sup>K<sup>–1</sup>, facilitating heat absorption. These properties make the EOC/MWCNT\nnanocomposite foam highly suitable for EMI shielding in sealing and\npackaging applications. The material’s attributes suggest substantial\npotential for diverse applications in aerospace technology, military\noperations, smart-wearable technology, and portable electronic devices.