Electrical and electromagnetic interference shielding properties of GNP-NiFe hybrid composite with segregate structure of conductive networks

Conductive polymer composites are widely used for electromagnetic radiation protection. Several strategies can be employed for creating shield materials with enhanced efficiency: the use of a hybrid filler that contains nanoparticles of different types, specific structural design, and methods for decreasing the percolation threshold. We present the study of segregated polymer composites (SPCs) with ultrahigh molecular weight polyethylene (UHMWPE) matrix and hybrid fillers of NiFe-decorated graphite nanoparticles (GNPs). The microstructure, electrical percolation behavior, and electromagnetic shielding efficiency of the developed SPCs as a function of conductive filler content are determined. The combination of the advantages of the segregated structure with a synergistic effect of a hybrid filler in (GNP-NiFe)/UHMWPE allows decreasing the percolation threshold to 0.45 vol. %. The enhanced shielding efficiency of 37 dB in the frequency range of 26-37.5 GHz is achieved at the filler content of 3.4 vol. % in 1 mm thick composite samples. The dominant shielding characteristic of absorption renders hybrid composites with a segregated structure promising materials.

Automated summary

This study investigates the microstructure, electrical percolation behavior, and electromagnetic shielding efficiency of conductive polymer composites with a segregated structure and hybrid fillers. The composite materials exhibit a lower percolation threshold and higher shielding efficiency under specific conditions.