Cu and Fe bimetallic heterostructure nanoparticles supported by carbon nanotube for multilayer structure electromagnetic interference shielding composite

Blindly increasing the content of conductive fillers is difficult to meet the requirements of flexibility and efficient shielding at the same time. In this paper, Cu and Fe bimetallic heterostructure nanoparticles are formed on the surface of CNTs by liquid-phase co-deposition. By taking into account the electrical conductivity of Cu and the magnetic conductivity of Fe, the electromagnetic properties of CNTs are greatly improved. By controlling the temperature gradient to realize the directional solidification of ice crystals combined with freeze-drying process, the flexible (Cu/Fe)@CNT/SA/CNF/PDMS composites with three-dimensional layered structure are successfully prepared. Adding only 1 wt% of (Cu/Fe)@CNT, the EMI-SE of the composite can reach 21 dB (the absorption loss ratio reaches 85.25 %), which is nearly 50 % higher than that of CNT/SA/CNF/PDMS composite. In addition, multi-scale modeling confirms that the introduction of Cu and Fe bimetallic heterostructure nanoparticles and three-dimensional multilayer structure greatly increase the absorption loss of the composites.