Electrified single-walled carbon nanotube/epoxy nanocomposite via vacuum shock technique: Effect of alignment on electrical conductivity and electromagnetic interference shielding

Electrified and non-electrified epoxy-based nanocomposites holding highly and randomly aligned single-walled carbon nanotube (SWCNT), respectively, were made by vacuum shock technique, where a DC electric field was used to align SWCNT. The alignment of SWCNTs in the electrified nanocomposites was verified via optical microscopy, SEM analysis, and Raman spectroscopy. Electrical characterization revealed that alignment of SWCNTs led to a significant improvement in electrical conductivity and electromagnetic interference shielding of the fabricated nanocomposites. For instance, the electrical conductivity of the electrified nanocomposites at 0.25 wt% and 0.60 wt% was 2.5 x 10(-8) and 5.1 x 10(-4) Sm-1, while the conductivity of non-electrified nanocomposites was 1.1 x 10(-11) and 5.6 x 10(-5) Sm-1, respectively. With 3.0 mm thickness and 0.60 wt% SWCNT loading, the electrified and non-electrified nanocomposites showed shielding effectiveness of 12.8 dB and 9.1 dB, respectively. These results revealed that electrification of SWCNT in epoxy-based nanocomposites improved the level of conductive network formation, thereby enhancing electrical properties of the nanocomposites. POLYM. COMPOS., 39:E1139-E1148, 2018. (c) 2017 Society of Plastics Engineers