Ternary heterogeneous core-shell structure CIP@PPy/MWCNTs composites for broadband microwave absorption

Abstract

Improving the microwave absorption performances of carbonyl iron powder by constructing heterogeneous core-shell structure is a known challenge. In this work, multiwalled carbon nanotubes have been successfully coated on the surface of carbonyl iron powder under the action of binder Polypyrrole. The microwave absorption performances of composites can be well adjusted by changing the average thickness of shell. Meanwhile, the maximum reflection loss can reach −64.29 dB with a thickness of 2.30 mm, while the maximum effective absorption bandwidth can achieve 5.80 GHz at a 1.77 mm thickness, which almost covers the whole Ku band. The excellent microwave absorption performance can be attributed to the synergistic effect of good impedance matching, magnetic loss, dielectric loss, conduction loss and transmission loss. Importantly, this novel ultra-thin composite is promising as candidate materials with excellent microwave absorption performances.