MnFe2O4/polyaniline/diatomite composite with multiple loss mechanisms towards broadband absorption

What is it about?

The research and development of absorbing materials with high absorbing capacity, wide effective absorption bandwidth, and lightweight has always been interesting. In this research, a facile hydrothermal method was used to prepare MnFe2O4, and the grain size of MnFe2O4 decreased with increasing hydrothermal temperature. When the size of MnFe2O4 nanoparticles is less than 10 nm, its quantum size effect and surface effect make its electromagnetic microwave absorption performance greatly optimized. Based on this, light porous diatomite and a three-dimensional polyaniline network are introduced. Diatomite is used as the base material to effectively reduce the agglomeration of MnFe2O4 quantum dots. The relatively high surface area introduced by a three-dimensional network of polyaniline promotes the orientation, interfacial polarization, multiple relaxation, and impedance matching, thereby generating further dielectric loss. Additionally, the magnetic properties of manganese ferrite and the strong electrical conductivity of polyaniline play an appropriate complementary role in electromagnetic wave absorption. The RLmin of MnFe2O4/PANI/diatomite is −56.70 dB at 11.12 GHz with an absorber layer thickness of 2.57 mm. The effective frequency bandwidth (RL < −10 dB) ranges from 9.21 to 18.00 GHz. The absorption mechanism indicates that the high absorption intensity is the result of the synergistic effect of impedance matching, conduction losses, polarization losses, and magnetic losses.

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Photo by Compare Fibre on Unsplash

Photo by Compare Fibre on Unsplash

Why is it important?

The MnFe2O4 quantum dots were loaded onto a porous diatomite disk covered with a three-dimensional network structure. This unique three-dimensional structure offered multiple attenuation mechanisms for electromagnetic wave absorption. Through a combination of reflection and scattering, interface polarization, conduction loss, and magnetic loss, the microwave absorption performance was significantly improved. This research provides a straightforward, cost-effectiveapproach to developing building decoration materials with highperformance microwave absorption.

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