Synthesis and electromagnetic properties of PANI/PVP/CIP core–shell composites

The polyaniline/polyvinylpyrrolidone/carbonyl iron powder (PANI/PVP/CIP) core–shell composites were prepared by in-situ polymerization in the PVP aqueous solution using toluenesulfonic acid (TSA) as dopant and ammonium persulfate (APS) as oxidant. The PANI/PVP/CIP was systematically investigated using scanning electron microscopy (SEM), FT-IR spectroscopy, electrochemical workstation, thermogravimetry analysis (TGA) and vector network analyzer. The results showed that the PANI/PVP can dramatically improve corrosion resistance of CIP. Compared with pure CIP, the PANI/PVP/CIP composites exhibited better impedance match and excellent microwave absorption properties. The reflection loss was found to <–10 dB in the 27.3–39.5 GHz range at thickness of 1.1 mm, and the minimum reflection loss of −15.28 dB was observed at 29.47 GHz with a matching thickness of 1.2 mm. A possible mechanism of the improved microwave absorption properties of the core–shell structure was obtained.