Electromagnetic Interference (EMI) Shielding of Single-Walled Carbon Nanotube Epoxy Composites

TLDR

The study fabricated SWNT–polymer composites and examined how SWNT wall defects and aspect ratio influence EMI shielding effectiveness. The composites achieved EMI shielding efficiencies above 20 dB, with 15 wt % SWNT reaching 49 dB at 10 MHz and 15–20 dB from 500 MHz to 1.5 GHz, and the shielding correlated with dc conductivity and was dominated by reflection.

Abstract

Single-walled carbon nanotube (SWNT)−polymer composites have been fabricated to evaluate the electromagnetic interference (EMI) shielding effectiveness (SE) of SWNTs. Our results indicate that SWNTs can be used as effective lightweight EMI shielding materials. Composites with greater than 20 dB shielding efficiency were obtained easily. EMI SE was tested in the frequency range of 10 MHz to 1.5 GHz, and the highest EMI shielding efficiency (SE) was obtained for 15 wt % SWNT, reaching 49 dB at 10 MHz and exhibiting 15−20 dB in the 500 MHz to 1.5 GHz range. The EMI SE was found to correlate with the dc conductivity, and this frequency range is found to be dominated by reflection. The effects of SWNT wall defects and aspect ratio on the EMI SE were also studied.