Lightweight multi-walled carbon nanotube buckypaper/glass fiber-epoxy composites for strong electromagnetic interference shielding and efficient microwave absorption

Multi-walled carbon nanotube buckypaper (BP) reinforced glass fiber-epoxy (GF/EP) composites were selected to fabricate electromagnetic interference (EMI) shielding and microwave absorbing materials. Six different composite configurations with 3.0 mm thick have been conceived and tested over the X-band (8.2-12.4 GHz). Flexible and low-density (0.29 g/cm(3)) BP provided a high specific EMI SE of 76 dB with controlled electrical conductivity. GF/EP/BP111 and GF/EP/BP101 composites possess EMI SE as high as of 50-60 dB, which can be attributed to the number of BP inserted and variation in the wave-transmitting layer of the laminates. Furthermore, the shielding mechanism was discussed and suggested that the absorption was the dominant contribution to EMI SE. GF/EP/BP110 laminate demonstrated suitable EMI performance (similar to 20 dB), whereas GF/EP/BP011 composite revealed excellent microwave performance, achieving an effective - 10 dB bandwidth of 3.04 GHz and minimum reflection loss (RL) value of - 21.16 dB at 10.37 GHz. On the basis of these results, GF/EP/BP composites prepared in this work have potential applications as both EMI shielding and microwave absorber materials given their facile preparation and lightweight use.