In this study, novel quaternary MWCNT/CuO/Fe3O4/PANI nanocomposites were synthesized with three different weight ratios of CuO/Fe3O4/PANI to MWCNT (1:3), (1:4), and (1:5), where all of its components were synthesized separately and then combined in specific weight ratios. CuO/Fe3O4/PANI transmission electron microscopy (TEM) images revealed that most nanoparticles were in a CuO/Fe3O4 hybrid form, with a narrow size distribution uniformly dispersed in a polymer background. The TEM and scanning electron microscopy (SEM) images of the MWCNT/CuO/Fe3O4/PANI nanocomposite revealed that the MWCNT was uniformly coated with CuO/Fe3O4/PANI. All three nanocomposites samples demonstrated superior microwave attenuation performance in terms of reflection loss and absorption bandwidth. The minimum reflection losses for MWCNT/CuO/Fe3O4/PANI nanocomposites (1:3), (1:4), and (1:5) were 45.7, 58.7, and 85.4, 87.4 dB, respectively. The absorption bandwidths (RL ≤ −10 dB) of MWCNT/CuO/Fe3O4/PANI nanocomposites (1:3), (1:4), and (1:5) were 6, 7.6, and 6 GHz, respectively.

Novel quaternary MWCNT/CuO/Fe3O4/PANI nanocomposites were synthesized with three different weight ratios of CuO/Fe3O4/PANI to MWCNT (1:3), (1:4), and (1:5), in a way, all its components were synthesized separately and then combined with certain weight ratios. TEM image of CuO/Fe3O4/PANI proved that most of the nanoparticles were in a form of CuO/Fe3O4 hybrids with narrow size distribution which were uniformly dispersed in a polymer background. TEM and SEM of MWCNT/CuO/Fe3O4/PANI nanocomposite indicated that MWCNT was covered with a uniform thickness of CuO/Fe3O4/PANI. All three samples of nanocomposites exhibited excellent microwave attenuation performance via both aspects of reflection loss and absorption bandwidth. Minimum reflection losses were 45.7, 58.7 and 85.4, 87.4 dB for MWCNT/CuO/Fe3O4/PANI nanocomposites (1:3), (1:4) and (1:5), respectively. Absorption bandwidths (RL ≤ -10 dB) were 6, 7.6 and 6 GHz, for MWCNT/CuO/Fe3O4/PANI nanocomposites (1:3), (1:4) and (1:5), respectively.