Microcellular Carbon Nanotube/Thermoplastic Elastomer Nanocomposite Foam to Amplify Absorption-Driven Electromagnetic Shielding Efficiency

The increasing proliferation of electronic devices has led to significant electromagnetic pollution, posing risks to communication systems and human health. Moreover, the trend toward miniaturizing electronic components complicates effective heat dissipation, leading to overheating and degraded performance. To address these issues, a microcellular nanocomposite foam composed of ethylene–octene copolymer (EOC) and multiwall carbon nanotubes (MWCNTs) was developed by using a blend of melt and solution mixing techniques. A chemical blowing agent was employed to introduce porous structures into the nanocomposite, resulting in a foam with a density range of 0.4–0.53 g/cm3 and a low percolation threshold at 4 wt %. This porous composite demonstrated an outstanding electromagnetic interference (EMI) shielding effectiveness of 25.5 dB in a 2 mm thick, 10 wt % MWCNT-loaded nanocomposite within the X-band frequency. Additionally, the composite foam exhibited a thermal conductivity of 0.25 Wm–1K–1, facilitating heat absorption. These properties make the EOC/MWCNT nanocomposite foam highly suitable for EMI shielding in sealing and packaging applications. The material’s attributes suggest substantial potential for diverse applications in aerospace technology, military operations, smart-wearable technology, and portable electronic devices.