Using γ-Fe2O3 to tune the electromagnetic properties of three-dimensional (3D) polypyrrole (PPy) and its broadband electromagnetic absorber

Electromagnetism such as gravity can be considered an omnipresent force, which plays an important role in the functional activities of organisms. However, electromagnetic waves with different frequencies have aroused various harmful factors in human beings and wildlife. With the tunable dielectric property, the material can get a controllable electromagnetic absorption range against different types of electromagnetic pollution. In this study, we reported that nano γ-Fe2O3 can regularly tune the dielectric properties of the three dimensional (3D) polypyrrole (PPy) aerogel. On the one hand, it has advantages such as a rapid synthesis strategy (only several minutes), facile purification process (with only water), and on the other hand, this aerogel based absorber can reach effective EA bandwidths of 6.76 GHz (≤−10 dB, 90% electromagnetic energy was attenuated) and 1.88 GHz (≤−20 dB, 99% electromagnetic energy was attenuated) simultaneously at a thickness of 2.5 mm.