Rational construction of wideband electromagnetic wave absorber using hybrid FeWO4-based nanocomposite structures and tested by the free-space method

Yang, Yiran; Logesh, K.; Mehrez, Sadok; Huynen, Isabelle; Elbadawy, Ibrahim; Mohanavel, V.; Alamri, Sagr

doi:10.1016/j.ceramint.2022.09.179

Cited by 13 publications

(6 citation statements)

References 32 publications

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“…The peaks and valleys of reflection over the frequency band correspond to the multiples of the quarter of the wavelength, inducing a destructive and constructive interference between the incident and reflected wave from the metal coat. As illustrated in Figure 6 through the absorption index, this phenomenon is expected for a given thickness (and dielectric properties) of the MUT [41]. A residual mismatch of the waveguide flanges used for the measurements explains also the light oscillations observed on the curves [42].…”

Section: Reflection and Absorption Performances In Rozanov Configurationmentioning

confidence: 60%

Influence of Aging and Mechanical Recycling on Microwave Absorption of PLA-Montmorillonite Nanocomposites Thin Films in Salisbury and Rozanov Configurations

Salah¹,

Beltrán²,

Danlée³

et al. 2023

Prime Archives in Nanotechnology

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The present paper aims to address the crucial concern of pollution induced by growing plastic waste and electromagnetic interference (EMI). Nanocomposites combining poly(lactic acid) (PLA) and organo-modified montmorillonite (OMMT) are synthesized and compression molded into thin films. A first set of samples, referred to as virgin, was kept as is, while a second set of samples were photochemically, thermally, and hydrolytically aged before mechanical recycling via extruding and second compression molding, resulting in the so-called recycled composite. The electromagnetic (EM) properties with a focus on microwave absorption performances of virgin and recycled samples are compared for various thicknesses and weight concentrations of OMMT in PLA matrix. The EM performances are gauges by Rozanov and Salisbury structures that consist of one-and two-layer stacks of composite films back-coated by a metal foil. Characterization in Rozanov configuration shows an average absorption index over the Ka-band of 29.3% and 21.1% for, respectively, virgin and recycled PLA reinforced with 4 wt.% OMMT. An optimization of the film thickness is proposed; up to 61.85% and 80% of absorption with a thickness of 1.4 mm and 3.75 mm, respectively, is reached with a metal back-coated rPLA-4%OMMT film. Characterization in the Salisbury configuration gives advantage to the recycled structure with an average absorption of 49.6% for a total thickness of 1.4 mm. The requirements of EMI shielding are met by PLA-OMMT composites with a certain benefit of the recycling process on EM performance.

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Section: Reflection and Absorption Performances In Rozanov Configurationmentioning

confidence: 60%

Influence of Aging and Mechanical Recycling on Microwave Absorption of PLA-Montmorillonite Nanocomposites Thin Films in Salisbury and Rozanov Configurations

Salah¹,

Beltrán²,

Danlée³

et al. 2023

Prime Archives in Nanotechnology

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“…This means that recycling modifies the microscopic organization and dispersion of OMMT in neat PLA matrix, resulting in more disorder in the composite system that affects the interfacial polarization mechanism. The presence of several circles has been observed in many works [38][39][40]; it is associated to the existence of multiple dielectric Debye dielectric relaxation phenomena in the samples, as well as interfacial polarization mechanisms active at the multiple interfaces between the inclusions and the hosting PLA medium.…”

Section: Electromagnetic Propertiesmentioning

confidence: 96%

Absorption Performances of PLA-Montmorillonite Nanocomposites Thin Films in Salisbury and Rozanov Configurations: Influence of Aging and Mechanical Recycling

Salah

Ouslimani²,

Danlée³

et al. 2022

Micromachines

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The present paper aims to address the crucial concern of pollution induced by growing plastic waste and electromagnetic interference (EMI). Nanocomposites combining poly(lactic acid) (PLA) and organo-modified montmorillonite (OMMT) are synthesized and compression molded into thin films. A first set of samples, referred as virgin, was kept as is, while a second set of samples were photochemically, thermally and hydrolytically aged before mechanical recycling via extruding and second compression molding, resulting in the so-called recycled composite. The electromagnetic (EM) properties with a focus on microwave absorption performances of virgin and recycled samples are compared for various thicknesses and weight concentrations of OMMT in PLA matrix. The EM performances are gauges by Rozanov and Salisbury structures that consist in one- and two-layer stacks of composite films back-coated by a metal foil. Characterization in Rozanov configuration shows an average absorption index over the Ka band of 29.3% and 21.1% for, respectively, virgin and recycled PLA reinforced with 4 wt.% OMMT. An optimization of the film thickness is proposed; up to 61.85% and 80% of absorption with a thickness of 1.4 mm and 3.75 mm, respectively, is reached with a metal back-coated rPLA-4%OMMT film. Characterization in Salisbury configuration gives advantage to the recycled structure with an average absorption of 49.6% for a total thickness of 1.4 mm. The requirements of EMI shielding are met by PLA-OMMT composites with a certain benefit of recycling process on EM performance.

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“…Understanding the adsorption mechanism wasconducive to interdiscipline development [45][46][47]. The hydrated ionic radius of Pb 2+ is 0.401 nm.…”

Section: Influence Of Ionic Strength On the Removal Ratementioning

confidence: 99%

“…The adsorption process of calcium sand for Pb(II), Cu(II) and Cd(II) is a rapid reaction: the removal rate can reach 80% of the maximum removal rate at 30 min, and the equilibrium state can be reached within 120 min. In the initial reaction stage, the adsorp- Understanding the adsorption mechanism wasconducive to interdiscipline development [45][46][47]. The hydrated ionic radius of Pb 2+ is 0.401 nm.…”

Section: Adsorption Kinetics Characteristicsmentioning

confidence: 99%

Study on the Adsorption Characteristics of Calcareous Sand for Pb(II), Cu(II) and Cd(II) in Aqueous Solution

et al. 2023

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The adsorption characteristics of calcareous sand for heavy metals Pb(II), Cu(II) and Cd(II) have been studied by batch testing in this study. The influence of the solid–liquid ratio, initial pH0 value, ionic strength, reaction time, temperature and initial concentration on adsorption has been investigated. Test results indicate that the initial pH and the solid–liquid ratio have a significant influence on the removal efficiency. At T = 30 °C, r = 1.0 g/L, and C0 = 1000 mg/L and for 12 h of reaction, the removal efficiencies of Pb(II), Cu(II) and Cd(II) are 97.6%, 88.15% and 65.72%, respectively. The adsorption quantity is more than 80% of the maximum adsorption quantity within 60 min, and the equilibrium adsorption can be reached within 120 min. The pseudo-second-order kinetic model is suitable to simulate the dynamic adsorption process of calcareous sand, and the isothermal process is found to obey the Langmuir model. Calcareous sand has a very high adsorption capacity for Pb(II), Cu(II) and Cd(II), with a maximum adsorption quantity Qm reached 1052.95 mg/g, 1329.84 mg/g and 1050.56 mg/g, respectively. Thermodynamic test results indicate that the adsorption process is spontaneously exothermic and that low temperature is favorable to the adsorption reaction.

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Rational construction of wideband electromagnetic wave absorber using hybrid FeWO4-based nanocomposite structures and tested by the free-space method

Cited by 13 publications

References 32 publications

Influence of Aging and Mechanical Recycling on Microwave Absorption of PLA-Montmorillonite Nanocomposites Thin Films in Salisbury and Rozanov Configurations

Influence of Aging and Mechanical Recycling on Microwave Absorption of PLA-Montmorillonite Nanocomposites Thin Films in Salisbury and Rozanov Configurations

Absorption Performances of PLA-Montmorillonite Nanocomposites Thin Films in Salisbury and Rozanov Configurations: Influence of Aging and Mechanical Recycling

Study on the Adsorption Characteristics of Calcareous Sand for Pb(II), Cu(II) and Cd(II) in Aqueous Solution

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