Achieving excellent electromagnetic wave absorption of ZnFe2O4@CNT/polyvinylidene fluoride flexible composite membranes by adjusting processing conditions

The magnetic ZnFe 2 O 4 nanoparticles were synthesized and combined with carbon nanotubes (CNTs) to form a unique tangled structure (ZnFe 2 O 4 @CNT), and then used as wave absorbing functional nanofillers of polyvinylidene fluoride (PVDF) matrix. The effects of ZnFe 2 O 4 @CNT functional nanofillers on the microstructure, crystallization behavior and electromagnetic wave absorption properties of PVDF were studied. The ZnFe 2 O 4 @CNT/PVDF composite membranes containing 7 wt% nanofillers presented an optimal reflection loss of −54.5 dB with a sample thickness of 2.4 mm when the processing temperature was 60 °C. If the processing temperature of 150 °C was adopted, the composite membranes with a thickness of only 2.0 mm surprisingly achieved an effective absorption of the whole X-band. The combination of interfacial polarization, polarization relaxation loss, dipole polarization, conductivity loss, and ferromagnetic resonance loss promoted the excellent microwave energy dissipation capacity of ZnFe 2 O 4 @CNT/PVDF system.