MWCNTs as Conductive Network for Monodispersed Fe₃O₄ Nanoparticles to Enhance the Wave Absorption Performances

Abstract

Magnetic oxides are widely used as electromagnetic (EM) wave absorbers. To promote the absorption efficiency, tremendous efforts have been contributed to adjusting the composite, structure, and size of magnetic loss materials. Employing carbon materials (CNTs, CF, graphene, PANI) is an efficient way to improve the dielectric loss of the matrix. Anchoring the tiny-monodispersed Fe 3 O 4 nanoparticles (NPs) onto the lightweight multi À walled carbon nanotubes (MWCNTs) leads to improve dielectric loss and impedance matching characteristic. Magnetic Fe 3 O 4 NPs along the one-dimensional nanotubes direction play a good synergetic role with MWCNTs due to the interfacial strong chemical and structure bonding. The as-synthesized Fe 3 O 4 / MWCNTs nanocomposites exhibit efficient EM wave absorption characteristics (R L avÀ10 dB) with a maximum reflection loss of À63.64 dB at 12.08 GHz and a diminutive thickness of only 1.6 mm. The magnetic Fe 3 O 4 NPs show strong chemical and structure bonding with the one-dimensional MWCNTs. This work may show a way to broaden the application of such kinds of lightweight high-performance absorbing materials frameworks.

Template‐Free Formation of Uniform Fe3O4 Hollow Nanoflowers Supported on Reduced Graphene Oxide and Their Excellent Microwave Absorption Performances

“…Meanwhile, the rapid development of military (radar invisible of aircrafts, tanks and targets) fields facilitate the regulation of microwave absorber to achieve high absorbing properties . As such, magnetic loss materials, for example transition metal oxides (MO x , M = Ni, Co, Fe) and spinel ferrites (MFe 2 O 4 , M = Ni, Co, Zn, Mn), are judiciously investigated due to their proper magnetic properties, natural abundance, low cost and good environmental benignity. However, the low efficiency and high density block their broad deployment and widespread commercialization.…”

One‐Pot Hydrothermal Synthesis of Co3O4/MWCNTs/Graphene Composites with Enhanced Microwave Absorption in Low Frequency Band

“…Therefore, the magnetic loss of the composites is only possibly occurred from the eddy current loss and natural resonance in gigahertz range . The eddy current loss associated with the magnetic loss can be calculated as follows: …”

In situ formation of Fe3O4/N-doped carbon coating on the surface of carbon fiber with improved electromagnetic wave-absorption property

“…CF [11][12][13] has high strength, good temperature and chemical resistance, exibility, processability 14 and plays an irreplaceable role in EM waveabsorbing materials of civil buildings and military equipment as compared to other EM wave-absorbing materials. 15,16 However, the complex permittivity of CF is extremely large, resulting in extremely low wave impedance of CF and poor matching between the wave impedance of CF and free space, 17 making the EM wave to be reected on the CF surface. Moreover, the CF lacks magnetic loss capacity that is detrimental to rapid attenuation of EM wave inside the CF.…”