Improvement of the Shielding Effectiveness of PMMA/MWCNTs/Ag Hybrid Composite for X-Band Application

Abstract

Herein, the PMMA/MWCNT/Ag hybrid composite films are prepared by solvent casting method to be used in an electrical application. The AC conductivity and dielectric characteristics have been investigated at room temperature. The electrical conductivity of the hybrid composite reaches a percolation critical concentration of 2.14×10-4 S/cm by Ag doping. For all PMMA/MWCNT/Ag hybrid composites, the frequency-dependent dielectric constant decreases as the frequency area widens. As the concentrations of MWCNT and Ag increase, the AC conductivity exhibits an increasing trend. The MWCNT and Ag content was found to significantly affect the SE of the given composites. A high electromagnetic (EM) shielding efficiency (SE) was achieved between 8.2 and 12.4 GHz (X-band). The highest EM attenuation of 18 dB at 12 GHz was achieved using 0.5 wt% MWCNT and Ag. The thermal analysis of the formed PMMA/MWCNT/Ag hybrid composites showed that exothermic reactions with the greatest weight loss took place between 200°C and 300°C. FESEM show that PMMA/MWCNT/Ag hybrid composites had  uniform dispersion of the  carbon  nano tube  and silver particles within the PMMA matrix .