Facile design and permittivity regulation of porous carbon and magnetic particles based composite nanofibers towards highly efficient electromagnetic wave absorption

Two-dimensional (PEA)2PbBr4 perovskite modified with conductive network for high-performance electromagnetic wave absorber

Synthesis and electromagnetic wave absorption performances of a novel (Mo0.25Cr0.25Ti0.25V0.25)3AlC2 high-entropy MAX phase

MXene/PEO aerogels with two-hierarchically porous architecture for electromagnetic wave absorption

Facile preparation of ZIF-8/ZIF-67-derived biomass carbon composites for highly efficient electromagnetic wave absorption

In modern times, with the rapid development of technology, science and economy, applications of electromagnetic (EM) wave absorption in both commercial and military fields have increased. Meanwhile, the problems brought by EM wave absorption have gradually become obvious, such as signal interference, back-radiation of microstrip radiators and so on. Furthermore, the impact of EM wave radiation on human health has also attracted much public attention. In this regard, the application of EM wave absorbing materials has become a focus of current research. Due to their unique chemical, physical, and mechanical properties, carbon nanotubes (CNTs), through certain modifications for light mass, wide range and strong absorption, have great potential to be used as excellent EM wave absorbents. This review highlights recent research into the modification of CNTs, with special emphasis on their EM wave absorbing ability.

Synchronously enhanced electromagnetic wave absorption and heat conductance capabilities of flower-like porous γ-Al2O3@Ni@C composites

HighlightsNon-magnetic bimetallic MOF-derived porous carbon-wrapped TiO2/ZrTiO4 composites are firstly used for efficient electromagnetic wave absorption.The electromagnetic wave absorption mechanisms including enhanced interfacial polarization and essential conductivity are intensively discussed.Modern communication technologies put forward higher requirements for electromagnetic wave (EMW) absorption materials. Metal–organic framework (MOF) derivatives have been widely concerned with its diverse advantages. To break the mindset of magnetic-derivative design, and make up the shortage of monometallic non-magnetic derivatives, we first try non-magnetic bimetallic MOFs derivatives to achieve efficient EMW absorption. The porous carbon-wrapped TiO2/ZrTiO4 composites derived from PCN-415 (TiZr-MOFs) are qualified with a minimum reflection loss of − 67.8 dB (2.16 mm, 13.0 GHz), and a maximum effective absorption bandwidth of 5.9 GHz (2.70 mm). Through in-depth discussions, the synergy of enhanced interfacial polarization and other attenuation mechanisms in the composites is revealed. Therefore, this work confirms the huge potentials of non-magnetic bimetallic MOFs derivatives in EMW absorption applications.

EM waves absorption properties of nitrogenous porous carbon derived from PANI fiber clusters carbonization

Generally, a silicone rubber and a chlorinated polyethylene(CPE) have been used as a binder for the development of high-performance composite EM(Electro Magnetic) wave absorbers. In this paper, the EM wave absorption performance of natural lacquer, which is newly proposed as a binder was investigated. The prepared MnZn ferrite EM wave absorbers are mixed with natural lacquer showed excellent EM wave absorption characteristics compared with MnZn ferrite EM wave absorbers which are mixed with the conventional binders. MnZn ferrite EM wave absorbers mixed with natural lacquer were prepared and their absorption ability was also investigated The EM wave absorbers are fabricated in different proportions of MnZn, or NiZn ferrite and natural lacquer, and their reflection coefficients are measured. The permittivity and permeability are calculated by using the measured reflection coefficients. The EM wave absorption abilities are calculated according to different thicknesses of the EM wave absorbers.

MoSe2 nanosheets decorated Co/C fibrous composite towards high efficiency electromagnetic wave absorption

RGO supported bimetallic MOFs-derived Co/MnO/porous carbon composite toward broadband electromagnetic wave absorption

It is well known that in low-dimensional systems, the motion of electrons is restricted. The confinement of electron in these systems has changed the electron mobility remarkably. This has resulted in a number of new phenomena, which concern a reduction of sample dimensions. These effects differ from those in bulk semiconductors, for example, electronphonon interaction effects in two-dimensional electron gases (Mori & Ando, 1989; Rucker et al., 1992; Butscher & Knorr, 2006), electron-phonon interaction and scattering rates in one-dimensional systems (Antonyuk et al., 2004; Kim et al., 1991) and dc electrical conductivity (Vasilopoulos et al., 1987; Suzuki, 1992), the electronic structure (Gaggero-Sager et al., 2007), the wave function distribution (Samuel & Patil, 2008) and electron subband structure and mobility trends in quantum wells (Ariza-Flores & Rodriguez-Vargas, 2008). The absorption of electromagnetic wave in bulk semiconductors, as well as low dimensional systems has also been investigated (Shmelev et al., 1978; Bau & Phong, 1998; Bau et al., 2002; 2007). However, in these articles, the author was only interested in linear absorption, namely the linear absorption of a weak electromagnetic wave has been considered in normal bulk semiconductors (Shmelev et al., 1978), the absorption coefficient of a weak electromagnetic wave by free carriers for the case of electron-optical phonon scattering in quantum wells are calculated by the Kubo-Mori method in quantum wells (Bau & Phong, 1998) and in doped superlattices (Bau et al., 2002), and the quantum theory of the absorption of weak electromagnetic waves caused by confined electrons in quantumwires has been studied based on Kubo’s linear response theory andMori’s projection operator method (Bau et al., 2007); the nonlinear absorption of a strong electromagnetic wave by free electrons in the normal bulk semiconductors has been studied by using the quantum kinetic equation method (Pavlovich & Epshtein, 1977). However, the nonlinear absorption problem of an electromagnetic wave, which has strong intensity and high frequency, in low dimensional systems is still open for study. In this book chapter, we study the nonlinear absorption of a strong electromagnetic wave in low dimensional systems (quantumwells, doped superlattices, cylindrical quantumwires and rectangular quantum wires) by using the quantum kinetic equation method. Starting from the kinetic equation for electrons, we calculate to obtain the electron distribution functions in low dimensional systems. Then we find the expression for current density vector and the nonlinear absorption coefficient of a strong electromagnetic wave in low dimensional The Nonlinear Absorption of a Strong Electromagnetic Wave in Low-dimensional Systems

Magnetic CoFe alloy@C nanocomposites derived from ZnCo-MOF for electromagnetic wave absorption

Construction of remarkable electromagnetic wave absorber from heterogeneous structure of Co-CoFe2O4@mesoporous hollow carbon spheres

High-performance electromagnetic wave absorbers based on Fe-based MOFs-derived Fe/C composites