Lightweight poly(vinylidene fluoride) based quaternary nanocomposite foams with efficient and tailorable electromagnetic interference shielding properties

Driven by rapidly growing demands in fields such as mobile electronics, aerospace and military, the need for functional materials with lightweight, good environmental stability and efficient electromagnetic interference (EMI) shielding properties has rose sharply. In this paper, quaternary nanocomposite foams comprising of poly(vinylidene fluoride) (PVDF), carbon nanotubes (CNTs), graphene nanoplatelets (GNPs) and Ni were developed by a melt blending and supercritical CO2 foaming technology. Compared with pure PVDF, the crystallization temperature of PVDF/2CNTs/2GNPs/12Ni nanocomposite increased remarkably from 139.0 to 144.9 degrees C. Rising the nanofiller loading from 0 to 16 wt % led to the enhancements of around four orders of magnitude in the storage modulus of PVDF nanocomposites as well as about three orders of magnitude in their complex viscosity. For a typical PVDF/2CNTs/2GNPs/12Ni nanocomposite, its EMI shielding effectiveness reached 32.2 dB, brought by dielectric loss and magnetic loss. The electrical conductivity and EMI shielding effectiveness of PVDF nanocomposite foam achieved the optimum values of 0.84 S/m and 19.4 dB, respectively, which originated from the introduction of pore structure and the gradual generation of nanofiller-nanofiller conductive networks. This study took a promising way toward the fabrication of materials with adjustable EMI shielding property in the fields of electronics and aerospace industries.