Improved microwave absorption and electromagnetic interference shielding properties based on graphene-barium titanate and polyvinylidene fluoride with varying content

Being lightweight, broadband, thin and highly efficient are the key desirable properties for microwave absorbers. We have successfully prepared reduced graphene oxide (rGO) coated with barium titanate (BT) using a simple method and a series of measurements were carried out to determine its morphology and structure. The composites of rGO@BT/poly(vinylidene fluoride) (PVDF) with filler amounts of 10, 15, 20 and 25 wt% exhibit broad frequency bands (<-10 dB) and the highest reflection coefficients of up to -33.2, -45.3, -32.9 and -22.8 dB, respectively, in the frequency range of 2-18 GHz with thicknesses of 1-5 mm. Furthermore, the electromagnetic interference (EMI) shielding effectiveness was measured and the theoretical calculations of SE_A and SE_R are displayed for comparison. The electrical conductivity and skin depth are shown as well for further investigation.