Contrasting Role of Defect-Induced Carbon Nanotubes in Electromagnetic Interference Shielding

Tuning of the defect is critical for specific application of a material worth exploring and researching. In view of this, additional defects have been incorporated in single-walled carbon nanotubes (SWCNTs) by subjecting them to camphor-mediated combustion and characterized by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, and electron paramagnetic resonance. Subsequently, we compared electromagnetic interference (EMI) shielding performance of SWCNTs vis-à-vis multiwalled carbon nanotube (MWCNT)-filled polystyrene (PS) nanocomposites. Interestingly, induced defects in SWCNT played a contrasting role with respect to MWCNT in their performance as EMI shielding materials. These findings have been correlated with the aspect ratio and percolation threshold of CNTs as well as dc conductivity of PS/CNT nanocomposites in the light of electromagnetic theory.