Preparation and properties of functional particle Fe₃O₄-rGO and its modified fiber/epoxy composite for high-performance microwave absorption structure

Abstract

Microwave absorbing materials have been becoming a countermeasure and security media for radio environment, and also been becoming the main military force attached by the world. In this study, experimental data, theoretical researches and FEKO-a 3D structure and electromagnetic field analysis simulation tool, namely, FEldberechnung bei Korpern mit beliebiger Oberflache, are effectively combined. Through systematic studies on electromagnetic parameters and microwave absorbing properties of high-performance absorbing functional particle Fe 3 O 4 -rGO (i.e. reduced graphene oxide), single-layer composite Fe 3 O 4 -rGO@EP/GF (epoxy/glass fiber) and multi-layer structure composite Fe 3 O 4 -rGO@EP/fiber, combined with the simulation calculations of material structures, design on the microwave absorption performances of fiber/resin structural composites is achieved. In particular, under the guidance of FEKO simulations, a multi-layer structure composite with two layers of Fe 3 O 4 -rGO@EP/GF with different Fe 3 O 4 -rGO added amounts as the absorbing layer and carbon fiber (CF) reinforced EP as the reflecting layer is prepared, which has an effective absorption bandwidth of 8. 43-12.40 GHz, almost covering the whole X-band, and RL min (minimum reflection loss) up to −34.60 dB at 10.37 GHz. The relevant experimental results are basically consistent with the FEKO simulation results. This study is helpful to improve the developing efficiencies and properties of microwave absorbing structure composites with both excellent mechanical properties and outstanding microwave absorbing performances, especially conducive to industrial productions. absorption intensity was −31.0 dB at −9.9 GHz. Se-Won Eun et al [2] produced the tested material glass/EP-MWCNT and introduced the 'split sample' test method, which, used to measure the reflection and absorption to electromagnetic waves, could analyze quantitatively the effects of layering by implementing layering with different thickness and position in the same sample, test results showed that the minimum reflection loss (RL min ) of the material prepared was −52.9 dB, resonance occurring at 10.01 GHz, and the effective absorption bandwidth was 8.3-12.4 GHz, almost covering the whole X-band. In addition, the effects of fiber lamination angle [3], pulp modification degree [4,5] and special hollow fiber [6] on the microwave absorbing properties of composites were studied too. used self-assembly technology to manufacture broadband periodic structural absorbing material with GO solution and PP fabric, through coupling multiple resonances and edge diffraction, the periodic structure absorbing material prepared had more than 90% absorption in the whole measurement frequency range (2-40 GHz, 75-110 GHz); in addition, it showed high absorption intensity (RL <−15 dB) over a wide frequency range (62.73 GHz). Wei-Li Song et al [8] accelerated the design of highefficiency microwave absorbing dielectric composites by allowing attenuation evaluation diagrams; based on this, combined with CST simul...

Regulating Percolation Threshold via Dual Conductive Phases for High-Efficiency Microwave Absorption Performance in C and X Bands

“…Figure f shows the RL plots of all samples under matching thickness for the broadest absorption bandwidth over 2–18 GHz, and S5 possesses the optimal microwave absorption performance with a maximum EAB value of 5.2 GHz, which covers 84% of the C band and 46% of the X band (4.64–9.84 GHz) under a thin thickness of 3.1 mm. The performance is superior to that of the most existing absorbers summarized in Table , − ,− which implies that S5 is a competitive candidate as an absorber focused on the C and X bands. In addition, the EM parameters and the microwave absorption performances of S5 with filler loadings of 55 and 75 wt % have also been measured for comparison.…”

“…Soft magnetic materials are believed as promising absorbers in the C and X bands due to their high complex permeability. , Nevertheless, ascribing to the insufficient attenuation properties driven by only magnetic loss, the synthesized Fe 3 O 4 nanowires only possess an EAB value of 3.2 GHz (6.0–9.2 GHz) with a thickness of 3.5 mm . The composite technology with a synergy of magnetic loss and dielectric loss has been found to exert a positive effect on enhancing the absorption properties. − Xue et al prepared Fe 3 O 4 –reduced graphene oxide (RGO) composites with a broader bandwidth of 3.97 GHz (8.43–12.4 GHz) by the combination of the dielectric and magnetic losses. The other Fe 3 O 4 –RGO composites also present similar performances .…”

“…14 The composite technology with a synergy of magnetic loss and dielectric loss has been found to exert a positive effect on enhancing the absorption properties. 15−18 Xue et al 15 prepared Fe 3 O 4 −reduced graphene oxide (RGO) composites with a broader bandwidth of 3.97 GHz (8.43−12.4 GHz) by the combination of the dielectric and magnetic losses. The other Fe 3 O 4 −RGO composites also present similar performances.…”

Construction of multilayer carbon magnetic heterostructures on the surface of carbon fibers to improve the absorption performance

“…The evaluation of the composites' microwave absorption characteristics was conducted through the calculation of RL. The following formula can be used to determine the RL for an absorber supported by a perfect conductor based on electromagnetic characteristics and transmission line theory 29–31 : where Z in refers to the input impedance and Z 0 is the free space impedance (376.7 Ω), which can be expressed as follows 32 : where d is the coating thickness, f is the frequency corresponding to the EMW, c is the velocity of light (3 × 10 8 km s −1 ), and μ r and ε r are the relative permittivity and permeability of the material, respectively.…”

Structural, Electromagnetic and Microwave Properties of Magnetite Extracted from Mill Scale Waste via Conventional Ball Milling and Mechanical Alloying Techniques

“…The complex permittivity (ε r -jε r "), complex permeability (µ -jµ"), and microwave absorption characteristics of magnetite composites produced at various milling durations and thicknesses of 1 and 2 mm were examined in the X and Ku bands (8-18 GHz) frequency ranges. The real components (ε and µ ) represent the storage capacity of electric and magnetic energies, respectively, whereas the imaginary parts (ε" and µ") indicate the loss capacity of electric and magnetic energies, respectively [67,68].…”