Multilayer-structured Ni-Co-Fe-P/polyaniline/polyimide composite fabric for robust electromagnetic shielding with low reflection characteristic

Fabrication of highly efficient electromagnetic shielding materials with low reflection and strong absorption characteristics is important to address the ever growing electromagnetic wave problem. Here, a facile and reliable strategy is proposed to prepare multilayer-structured nickel-cobalt-ferrum-phosphorus/polyaniline/polyimide (Ni-Co-Fe-P/PANI/PI) fabrics via a successive step of in-situ polymerization and electroless plating. By controlling the composition of Ni-Co-Fe-P alloy judiciously, the dielectric-magnetic loss characteristics of Ni-Co-Fe-P/PANI/PI fabrics can be balanced, especially the 50Ni-Co-Fe-P/PANI/PI (CNi2+:C-Co(2+):C-Fe(2+) = 2:1:1) fabric, displaying the highest electromagnetic shielding effectiveness (40.5-69.4 dB) at X-band frequency range, which is superior to those of traditional metallic fabrics as well as carbon materials or conductive polymers coated fabrics with only 0.2 mm thickness. The proper impedance matching characteristic ensures that most of incident electromagnetic waves are penetrated into material rather than directly reflected back. The residual electromagnetic waves are dissipated through the dielectric-magnetic loss synergistic effect from PANI and Ni-Co-Fe-P layer. In addition, the advantageous features in practical application properties allow for robust and stable electromagnetic shielding efficiency and harsh environments resistent.