Synergistic effect of graphene nanoplate and carbonized loofah fiber on the electromagnetic shielding effectiveness of PEEK-based composites

Graphene nanoplate (GNP)/carbonized loofah fiber (CLF)/polyether-ether-ketone (PEEK) composites were fabricated by compressive moulding technology. A three-dimensional multi-interface conductive network of CLF and GNP within the matrix was observed under scanning electron microscope. The combination of CLF and GNP improve the electromagnetic shielding performance of composites in the X-band region. The average total shielding effectiveness of the composite reached 27.1 dB at the addition of 9 wt% CLF. The electromagnetic shielding performance of the composites is significantly improved due to the gradual formation of the conductive network structured with CLF and GNP. The shielding mechanism of composites is dominated by absorption, due to the contribution of absorption to shielding effectiveness is much greater than that of the reflection. Furthermore, the composites exhibit prominent mechanical property and thermal stability, which the compressive strength and modulus of GNP/ CLF/PEEK composite with 3 wt% CLF loading reaches 114.6 MPa and 0.71 GPa and the temperature of all composites reaches 550 degrees C at 10% mass loss. The results indicate that the composite material shows potential applications in extremely harsh environments such as aerospace, warships, and special devices as structural and functional integrated materials. (C) 2018 Elsevier Ltd. All rights reserved.