The composites were synthesised by a two-step hydrothermal and in-situ polymerisation method, with Zn ferrite (2-30nm particles) used to adjust the impedance matching and improve polyaniline magnetic loss capability.

“The synergy of fluffy structure, dielectric loss, magnetic loss, interfacial polarisation and phase cancellation effect lead to the attenuation of microwave energy,” according to the University. ” Furthermore, the fluffy structure enhanced the microwave transmission path and attenuation efficiency. These factors make this composite a good microwave absorber and an ideal material in the electromagnetic wave absorption field.”

Tested in Ku band, return loss is below −10dB and minimum reflection loss is −54.4dB at 17.6GHz with the coating thickness of 1.4mm, according to the abstract of ‘Structure and microwave absorption properties of polyaniline/Zn ferrite composites‘ published in Nano from World Scientific.

In the face of increasing microwave emission through the rising popularity of mobile phones, computers and wireless routers, these materials have great applications in information security, healthcare and electronic countermeasures, said the university. Functional materials made from polyaniline and ferrite are easy to synthesise, lightweight and thin.