Fig. 1. Variation of reflection loss of graphene/PLA composite samples with frequency

Fig. 2. Variation of complex dielectric constant of graphene/PLA composite samples with frequency. (a) Real part of complex dielectric constant; (b) imaginary part of complex dielectric constant

Fig. 3. Variation of conductivity of graphene/PLA composite samples with graphene content

Fig. 4. Variation of reflection loss of graphene/nano-Fe₃O₄/PLA composite samples with frequency

Fig. 5. Variation of complex dielectric constant of graphene/nano-Fe₃O₄/PLA composite samples with frequency. (a) Real part of complex dielectric constant; (b) imaginary part of complex dielectric constant

Fig. 6. Variation of complex permeability of graphene/nano-Fe₃O₄/PLA composite samples with frequency. (a) Real part of complex permeability; (b) imaginary part of complex permeability

Fig. 7. SEM cross-sectional images of pure PLA sample and graphene/PLA composite samples. (a) Pure PLA sample; (b) 5% graphene/PLA composite sample; (c) 6% graphene/PLA composite sample; (d) 7% graphene/PLA composite sample; (e) 8% graphene/PLA composite sample; (f) 9% graphene/PLA composite sample

Fig. 8. SEM cross-sectional images of graphene/nano-Fe₃O₄/PLA and 5% graphene/PLA composite sample. (a) 1% graphene/20% nano-Fe₃O₄/PLA composite sample; (b) 3% graphene/20% nano-Fe₃O₄/PLA composite sample; (c) 5% graphene/20% nano-Fe₃O₄/PLA composite sample; (d) 5% graphene/PLA composite sample

Fig. 9. Schematic of wave absorption mechanism