Microwave absorption enhancement of CIP/PANI composites

The carbonyl iron powder and polyaniline (CIP/PANI) composites have been synthesized by in situ polymerization method and it is found that the doped acid mole ratio has great influence on the properties of the composites. At proper mole ratio of doped acid to aniline, a non-magnetic phase appears due to interaction between the micro-sphere CIP and the PANI polymer, which weakens the magnetic loss and dielectric loss of the composite simultaneously, but improves the impedance matching of the composite and strongly enhances the microwave absorbing properties. The magnetic properties of CIP/PANI composites can be well described using modified Bruggeman effective medium theory.

► A non-magnetic FeN phase appears between the CIP powders and the PANI polymer.
► The MS spectrum, magnetic hysteresis loops prove the existence of FeN, indirectly.
► The FeN phase can strongly enhance the microwave absorbing properties.
► The magnetic properties of PANI/CIP can be well described using modified BG EMT.