Porous Fe@Fe3O4-C Nanocomposite Using Polyvinyl Alcohol Sponge as Template for Microwave Absorption

Abstract

In order to obtain a material with excellent microwave absorption performance, polyvinyl alcohol (PVA) sponge was employed as the template. The porous structure of the sponge can facilitate faster and more uniform diffusion of the ferric nitrate liquid during the dipping and obtain a uniform distribution of the ferromagnetic particles, which serves as a functional phase to enhance the microwave absorption properties. The Fe@Fe 3 O 4-C nanocomposite can then be fabricated through a dipping/carbonization process. The special core-shell structure effectively improves the dielectric and magnetic loss and provides proper impedance matching. The results indicate that the prepared samples show excellent microwave absorption performance, with maximum effective absorption bandwidth up to 7.9 GHz at a thickness of 2.27 mm. The maximum reflection loss can reach À48.36 dB at 9.6 GHz. Therefore, it is feasible to use PVA sponge as a template to fabricate porous Fe@Fe 3 O 4-C nanocomposite with excellent microwave absorption performance.

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In-situ Growth of MAX Phase Coatings on Ecological Carbon and their Terahertz Shielding Properties Investigations

“…For instance, structures with speci c interface contacts (e.g. core-shell structure, sandwich-like structure and porous foam structure) could induce interfacial polarization to dissipate electromagnetic waves, and thus improve electromagnetic shielding effectiveness [7][8][9][10][11] . Among them, materials with porous structures show the merits of large speci c surface area, lightweight and high strength to weight ratio, making them attract great attentions.…”