Analysis of the electromagnetic interference shielding effectiveness of polystyrene-SWCNT nanocomposite in X-band frequencies

In this work, polystyrene/single-walled carbon nanotube nanocomposites (PS-SWCNT) at three different concentrations of carbon nanotubes namely 0.1, 2, and 5 wt% with thickness of 2 mm were fabricated using a solution method to serve as an electromagnetic wave shield at X-band frequencies ranging from 8.2 to 12.4 GHz. FESEM analysis exhibited a uniform dispersion state of the reinforcement phase into the polymer matrix. XRD test showed the presence of the CNTs in PS matrix via exhibiting the characteristic peaks at specific angles. Also, mechanical test was carried out on the samples. Following this, the samples were subjected to measurement of electromagnetic interference shielding effectiveness (EMI SE) using a two-port vector network analyzer. This involved analyzing the absorption, reflection, and transmission of electromagnetic waves for each sample. The findings revealed a significant increase in EMI SE with the higher concentration of the CNTs in the polymer matrix, in such a way that the total shielding effectiveness of the samples in 5 wt%, and 0.1 wt% was recorded at 16 dB and 3 dB, respectively. The remarkable EMI shielding properties of PS-SWCNT nanocomposite can be mainly attributed to high electrical conductivity, high dielectric loss, and more importantly the multiple reflections due to presence of the nanofillers. Consequently, this material holds promise for attenuating electromagnetic wave interference at X-band frequency range.