Enhancement of electromagnetic interference shielding from the synergism between Cu@Ni nanorods and carbon materials in flexible composite films

Abstract

A series of composite films containing poly(vinylidene fluoride) (PVDF), carbon nanotubes (CNTs), graphene and bimetallic nanorods, in which copper was wrapped with nickel (Cu@Ni), were fabricated via a facile preparation method of solution casting and compression molding. The electrical conductivity, thermal conductivity, and electromagnetic interference shielding effectiveness of the PVDF/CNT/graphene/Cu@Ni composite films were adjusted by varying the Cu@Ni content. A stronger EMI shielding performance (158.8 dB mm-1) was achieved due to the synergistic effects between Cu@Ni nanorods and carbonaceous nanofillers (CNTs and graphene) compared with our previous studies. The Cu@Ni nanorods particularly contributed both magnetic loss and dielectric loss to the electromagnetic wave. The increased electrical and thermal conductivity with Cu@Ni content facilitated the films' ability to transform electromagnetic wave energy into Joule heat. Moreover, the composite films possessed enhanced mechanical strength, flexibility and electrical stability due to the ordered filler network between the PVDF and the fillers.