Fabrication of a flexible and efficient electromagnetic wave absorber based on reduced graphene oxide/Fe7Co3 filled into polydimethylsiloxane

A flexible and efficient reduced graphene oxide/Fe7Co3/polydimethylsiloxane (rGO/Fe7Co3/PDMS) composite electromagnetic wave (EMW) absorber was prepared by a fast and simple liquid reduction and subsequent liquid phase blend method. The introduction of rGO tunes the dielectric constant and dielectric loss of the composite absorber, and Fe7Co3 imparts magnetic loss characteristics to the material. The rheological properties of PDMS enable rGO/Fe7Co3 to be well dispersed within it, forming a homogeneous structure, which contributes to the synergistic effect of the components and improves the impedance matching conditions and attenuation capability of the composite absorber. It is worth noting that the EMW absorption properties of the composites can be effectively adjusted by changing the amount of rGO/Fe7Co3 added to the PDMS. When the amount of rGO/ Fe7Co3 is 8.00 wt%, rGO/Fe7Co3/PDMS-8 shows superior EMW absorption property. The minimum reflection loss (RLmin) of - 52.58 dB at 1.80 mm, and the widest effective absorption bandwidth (EAB, RL<- 10 dB) can reach 6.40 GHz (11.40-18.00 GHz) at only 1.60 mm. Furthermore, the twist test shows that the RLmin and widest EAB of rGO/Fe7Co3/PDMS-8 remained at 92.64 % and 97.50 % of its initial values after 1500 twists, respectively, demonstrating its excellent flexibility. These results indicate that such rGO/Fe7Co3/PDMS-8 composite is very promising as a next generation flexible and efficient EMW absorbing material.