Effect of graphene content on microwave absorption properties of fused deposited composite samples

Graphene/polylactic acid single-component composites and graphene/nano-Fe₃O₄/polylactic acid twocomponent composites were rapidly prepared using fused deposition molding technology, and the effect of graphene content on absorbing properties was examined. Single-component samples exhibit better wave absorption performance with an 8% mass fraction of graphene. In the two-component composite, with a constant nano-Fe₃O₄mass fraction, increasing graphene content obviously improves the wave absorption performance of the sample. Furthermore, the wave absorption performance of two-component composite samples is better than that of the single-component composite sample. Folds formed by graphene coating on the substrate surface can increase the number of multiple reflections of electromagnetic wave. However, when graphene content is too large, electron scattering, which is generated by graphene agglomeration, affects the wave absorption effect. Compared with the single-component composite sample, the two-component composite sample has more types of micro interfaces under the dual action of graphene and nano-Fe₃O₄, which renders electromagnetic wave propagation path more complex, thereby consuming more energy. Therefore, compounding different types of absorbing agents can effectively improve the wave absorption performance of the material.