Gradient 3D-printed honeycomb structure polymer coated with a composite consisting of Fe3O4 multi-granular nanoclusters and multi-walled carbon nanotubes for electromagnetic wave absorption

Electromagnetic wave radiation has adverse health effects on humans and can hamper nearby electronic devices? regular operations. Therefore, the need to develop new materials with a substantial wave absorption property, a broad absorption bandwidth in a wide incident angle, and lightweight is of enormous technological interest worldwide. Here we report the experimental frequency-dependent permittivity and permeability behaviors of the composite consisting of Fe3O4 multi-granular nanoclusters (MGNCs) and multi-walled carbon nanotubes (MWCNTs). We also apply the results for the starting point for the gradient honeycomb structure design and optimization. We study the effect of the tilted angle on the reflection loss (RL) by finite element analysis (FEM). We obtain a flat RL over the X-band for the regular honeycomb structure with a 0 degrees tilted angle. An increase in the tilted angle from 0 degrees to 4 degrees increases the RL, and a peak is formed at the maximum tilted angle of 4 degrees. Coating the regular honeycomb structure with a thin layer of MGNC/MWCNT enhances the electromagnetic shielding (EMI). Furthermore, as tilted angle increases for the coated honeycomb structure from 0 degrees to 4 degrees, SE increases dramatically over the frequency range from 8.2 to 12.4 GHz at incident wave angles of 0 degrees and 90 degrees.