Lightweight and flexible Ni-Co alloy nanoparticle-coated electrospun polymer nanofiber hybrid membranes for high-performance electromagnetic interference shielding

Abstract

Low-density, flexible and high-performance electromagnetic interference (EMI) shielding materials are urgently required to address the increasingly serious problem of radiation pollution. Ni-Co alloys with intrinsic conductivity and magnetism are good candidates for providing excellent EMI shielding performance. However, their high density and poor flexibility severely restrict their further applications in some specific fields. Herein, lightweight and flexible Ni-Co alloy nanoparticle-coated PAN-PU (P@Ni-Co) nanofiber membrane is fabricated through the combination of the electrospinning technique and the electroless deposition process, and it is employed as an effective EMI shielding material. Due to its remarkable conductivity of 1139.6 S/cm and the satisfactory saturation magnetization value of 49.6 emu/g, P@Ni-Co hybrid membrane with a thickness of 0.180 mm and a density of 0.59 g cm−3 exhibits excellent electromagnetic interference shielding effectiveness (EMI SE) of >68 dB over a wide frequency band (8–26.5 GHz); moreover, the average EMI SE reached as high as 77.8 dB with an absolute EMI shielding effectiveness (SSET) of 7325.8 dB cm2·g−1, which are higher than those for most of the reported EMI shielding materials. Compared to reflection, absorption makes a much larger contribution to the total EMI shielding effectiveness. These results suggest that Ni-Co alloy nanoparticle-coated PAN-PU nanofiber membrane would be very promising for applications as a thinner and lighter EMI shielding material.