Cake-like flexible carbon nanotubes/graphene composite prepared via a facile method for high-performance electromagnetic interference shielding

Graphene (G) and carbon nanotubes have attracted significant attention in electromagnetic interference (EMI) shielding area due to the advantages of high electrical conductivity, high thermal conductivity, low density, large surface area and excellent mechanical property. The 2D structural G combining with 1D conductive carbon nanotubes are expected to generate synergistic effect and obtain better EMI shielding effectiveness (SE). Here, only using simple filtration and calcination method, 3D interconnected electrical conductive network was successfully constructed for the synergistic effect of thermally treated G and reduced oxidized multi-wall carbon nanotubes (r-OCNTs). And then the interconnected high electrical conductive and flexible TCG/PDMS composite cake (TCGPC) was obtained with poly dimethylsiloxane (PDMS) coated onto thermally treated r-OCNTs/G composite cake. The electrical conductivity of TCGPC reached up to 15.15 S cm−1, which was ascribed to the synergistic effect of r-OCNTs and G. The EMI shielding effectiveness (SE) of the flexible TCGPC (∼1.0 mm) increased from ∼50.3 dB for G/PDMS composite cake to ∼67.3 dB in X-band. Futhermore, even after repeatedly bending for 10000 cycles, the EMI SE of the flexible TCGPC still remained 62.7 dB.