Controllable preparation of 3D porous Co/Mo2C/C aerogels: Synergizing multifunctionality with efficient microwave absorption performance

Efficient microwave absorption induced by hierarchical pores of reed-derived ultralight carbon materials

Nitrogen-doped and Fe-filled CNTs/NiCo2O4 porous sponge with tunable microwave absorption performance

Polyimide composite aerogels towards highly efficient microwave absorption and thermal insulation

Facile synthesis of LaNiO3 microspheres with efficient broad band microwave absorption performance

Exploring glass fibers modification conditions and designing lightweight and efficient absorbers based on glass fiber @polypyrrole

The development of composites with highly efficient microwave absorption (MA) performance deeply depends on polarization loss, which can be induced by charge redistribution. Considering the fact that polarization centers can be easily obtained in graphene, herein, iron phthalocyanine (FePc) is used as polarization site to coordinate with nitrogen-doped graphene (FePc/N-rGO) to optimize MA performance comprehensively. The factors influencing MA properties focus on the interaction between FePc and N-rGO, and the change of dipole moments. The density functional theory (DFT) results demonstrated that FePc has strong interaction with N defect sites in graphene. The charge loss for FePc and charge accumulation for N-rGO occurred, leading to great increase of dipole moment, and the increased dipole moment can be acted as a descriptor to evaluate the enhanced polarization loss. Due to high charge redistribution capacity of N defect sites and FePc polarization centers, the FePc/N-rGO showed excellent MA properties in C band, and the minimum reflection loss value can reach -49.3dB at 5.4GHz with thickness of 3.8mm. In addition, the fabric loaded with FePc/N-rGO showed good heat dissipation property. This work opens the door to the development of MA performance bound to polarization site with dipole moment.

Thin composite films hold great promise for microwave devices for microwave absorption. This work mainly focuses on the investigation of the microwave absorption and mechanical studies of a composite thin film of activated carbon and manganese ferrite as conductive fillers within a polyvinylidene fluoride (PVDF) matrix. The production of activated carbon was successfully accomplished using a pyrolysis technique. Composite films consisting of polyvinylidene fluoride (PVDF) and activated carbon‐manganese ferrite were fabricated using a solution blending method. The composite films maintained a consistent concentration of activated carbon at 5 wt%. The characterization of the materials was conducted using scanning electron microscopy and X‐ray diffraction. The composite consists of 3 wt% of MnFe 2 O 4 and 5 wt% Activated carbon/PVDF showed exceptional absorption properties and achieved a minimum reflection loss of around −38 dB at a frequency of 8–12 GHz at a thickness of 2 mm. Significantly, the composite film exhibited a greater tensile strength than the PVDF film. The results of our study highlighted the enhanced microwave absorption and economical manufacturing technique for producing composite films. These films exhibit promising microwave‐absorbing properties in stealth applications. Highlights A facile strategy to fabricate thin film PVDF composites was proposed. Novel activated carbon was synthesized to enhance the conductivity. Achieved reflection loss of around −38 dB at a frequency of 8–12 GHz. Synergistic effects of fillers enhanced dielectric and magnetic losses. Exhibited efficient mechanical performance and microwave absorption.

Understanding the efficient microwave absorption for FeCo@ZnO flakes at elevated temperatures a combined experimental and theoretical approach

Rime-like carbon paper@Bi2S3 hybrid structure for efficient and broadband microwave absorption

In this work, we introduce a simple, efficient and low-cost process, where silver nanoparticles (AgNPs) are mixed in TEMPO-oxidized microcrystalline cellulose (TOMCC) by electroless plating successfully obtain a lightweight, green microwave absorber (TOMCC/AgNPs). We characterize and analyze the physicochemical properties and surface morphology of TOMCC/AgNPs using SEM, EDS, UV–Vis, XRD, XPS, BET, Raman spectroscopy and, thermal behavior, while analyzing the electromagnetic absorption of fabricated TOMCC/AgNPs through a vector network. Our results show that the optimal reflection loss value is − 51 dB at 4.7 GHz, with a corresponding effective absorption bandwidth of 4 GHz, and the thickness of the absorber is 2 mm, containing 50% TOMCC/AgNPs. Even at 400 ℃, the absorber can still maintain efficient microwave absorption performance. As a green, lightweight, and efficient microwave absorber, the prepared TOMCC/AgNPs have considerable application prospects in the field of microwave absorption, such as stealth technology.

Magnetic isocyanate-based polyimide composite foam for efficient microwave absorption

The continuous miniaturization and high integration of electronic devices have intensified heat dissipation and electromagnetic interference issues while also limiting the simultaneous application of thermal interface and microwave absorbing materials. Thus, developing interface materials with both high thermal conductivity and efficient microwave absorption has become crucial. Herein, a core–shell rGO‐BN heterostructure filler is reported with both high thermal conductivity and efficient microwave absorption performance, which is fabricated through the self‐assembly of polydopamine‐coated spherical boron nitride (BN) and graphene oxide (GO) and followed by thermal reduction. The rGO‐BN is used as thermally conductive/microwave absorption filler and blended with boron nitride nanosheet (BNNS) and polybutadiene (PB) to prepare rGO‐BN/BNNS/PB composites. When the mass fractions of rGO‐BN and BNNS are 45 and 13 wt.%, respectively, the rGO‐BN/BNNS/PB composites exhibit thermal conductivity of 5.94 W m −1 K −1 , minimum reflection loss of −50.10 dB (3.9 mm, 8.42 GHz), and effective absorption bandwidth of 5.25 GHz (2.7 mm, 10.70–15.95 GHz), surpassing the current state of the art. This work provides fresh perspectives for overcoming the trade‐off between high thermal conductivity and excellent microwave absorption.

Compositional and morphological design of heterojunction modified by Schottky junction as highly efficient microwave absorbers

With the rapid advancement of 5G communication and artificial intelligence technologies, the ubiquitous deployment of electronic apparatuses has raised pressing issues relating to signal interference and electromagnetic pollution, driving intensive research into microwave-absorbing materials. This article proposed a defect engineering-driven strategy to endow nanostructured TiO2 with excellent microwave absorption performance through the synergistic optimization of oxygen vacancies and core–shell nanostructure design. By precisely controlling the hydrogenation temperature (300–450 °C) and TiO2/NaBH4 ratio (1–4), we achieved tunable microwave absorption performance. Under optimal conditions, the nanomaterial exhibited a RLmin of −32.95 dB and an effective absorption bandwidth of 2.794 GHz, showing great promise for electromagnetic interference shielding in next-generation communication devices and radar systems. The concentration of oxygen vacancies was the core factor affecting the absorption performance. Incorporating oxygen vacancies not only enhanced defect-induced polarization and interface polarization effects but also strengthened conductivity loss by increasing carrier concentration. The collaborative interplay of these three mechanisms endows the nanostructured material with a superior microwave attenuation capability. The findings provide theoretical and practical guidance for developing lightweight, broadband, and highly efficient black TiO2-derived microwave absorbers. Our findings offer practical guidance for developing advanced microwave absorbers for next-generation aerospace radar and communication systems.

Amorphous structures may play important roles in achieving highly efficient microwave absorption performance due to the polarization losses induced by the disorders, vacancies and other functional groups existed in them. Herein, a kind of amorphous TiO2/rGO composite (a-TiO2/rGO) was successfully fabricated via a facile one-step solvothermal method. The complex permittivity of the composites can be regulated by adjusting the addition of precursor solution. The minimum reflection loss of a-TiO2/rGO composites reached −42.8 dB at 8.72 GHz with a thickness of 3.25 mm, and the widest efficient absorption bandwidth (EAB) was up to 6.2 GHz (11.8 to 18 GHz) with a thickness of only 2.15 mm, which achieved the full absorption in Ku band (12 to 18 GHz). Furthermore, the EAB was achieved ranging from 3.97 to 18 GHz by adjusting the thickness of the absorber, covering 87.7% of the whole radar frequency band. It is considered that the well-matched impedance, various polarization processes, capacitor-like structure and conductive networks all contributed to the excellent microwave absorption of a-TiO2/rGO. This study provides reference on constructing amorphous structures for future microwave absorber researches and the as-prepared a-TiO2/rGO composites also have great potential owing to its facile synthesis and highly efficient microwave absorption.