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Electromagnetic shielding is a critical function in various technologies, which is ideally achieved using a metal that reflects all incident radiation below its plasma frequency. Using high-resolution finite difference frequency domain simulations at microwave/RF frequencies, we show that the same efficacy can be achieved using a disordered collection of metal nanoparticles embedded in a flexible material. The mechanism underlying the reflection in the composite material is wave localization, disallowing the propagation of radiation up to the plasma frequency of the metal that constitutes the particles. We realize such a biopolymer composite using DNA–CTMA (deoxyribonucleic acid–cetyltrimethylammonium complex) as a support structure for Ag nanoparticles. This biopolymer composite exhibits an extremely high shielding effectiveness, close to that of a metal slab, because of Anderson localization of the electromagnetic waves. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multi-interfaced Ni/C@RGO/PTFE composites were designed for electromagnetic protection application. • Ni/C@RGO/PTF possessed outstanding electromagnetic wave absorption and electromagnetic interference shielding properties. • Carbon coating and PTFE matrix acted as dual protective barriers for metal Ni. • Ni/C@RGO/PTFE exhibited excellent environmental stability and durability. To efficiently address the growing electromagnetic pollution problem, it is urgently required to research high-performance electromagnetic materials that can effectively absorb or shield electromagnetic waves. In addition, the stability and durability of electromagnetic materials in complex practical environments is also an issue that needs to be noticed. Therefore, the starting point for our problem-solving is how to endow magnetic/dielectric multi-interfaced composite materials with excellent electromagnetic protection capability and environmental stability. In this study, magnetic/dielectric multi-interfaced Ni/carbon@reduced graphene oxide/polytetrafluoroethylene (Ni/C@RGO/PTFE) composites were developed to utilize as excellent EWA (electromagnetic wave absorption) and EMI (electromagnetic interference) shielding materials. Due to their diverse heterogeneous interfaces, rich conductive networks, and multiple loss mechanisms, the Ni/C@RGO/PTFE composite exhibits an optimal reflection loss of −61.48 dB and an effective absorption bandwidth of 7.20 GHz, with a filler loading of 5 wt%. Furthermore, Ni/C@RGO/PTFE composite films have an optimal absorption effectiveness value of 9.50 dB and an absorption coefficient of 0.49. Moreover, Ni/C@RGO/PTFE can hold high EWA performance in various corrosive media and maintain more than 90% of EMI shielding effectiveness, which can be attributed to the carbon coating and PTFE matrix acting as dual protective barriers for the susceptible metal Ni, thus obviously improving the stability and durability of composites. Overall, this work presents an effective strategy for the growth of high-performance EWA and EMI shielding materials with outstanding environmental stability and durability, which have wide application prospects in the future. [ABSTRACT FROM AUTHOR]

SiC f /BN/SiBCN composites were prepared through the technique of polymer infiltration pyrolysis (PIP). To enhance the electromagnetic interference (EMI) shielding effectiveness (SE), 20 wt% of Ti 3 SiC 2 was incorporated into the composites. The study investigated the influence of different oxidation temperatures (1300 °C, 1400 °C, and 1500 °C) on both the mechanical properties and EMI SE of the composites. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were utilized to analyze the phase and microstructure of the composites, while characterizing their mechanical properties and EMI SE. The outcomes revealed a decline in the mechanical properties of the composites following high temperature oxidation, with the formation of SiO 2 and TiO 2 as the main oxidation products. Notably, an oxide layer formed on the material's surface at 1400 °C acted as a barrier to oxygen diffusion, facilitating self-healing of pores and cracks and thereby enhancing material protection. Moreover, the material oxidized at 1400 °C demonstrated a remarkable synergy between impedance matching and electromagnetic loss, resulting in the optimum EMI SE. The EMI SE of this material was 6.35% higher than the total shielding effectiveness at room temperature and effectively shielded 99.88% of electromagnetic waves. [ABSTRACT FROM AUTHOR]

Since electromagnetic pollution is detrimental to human health and the environment, numerous efforts have been successively made to achieve excellent electromagnetic interference shielding effectiveness (EMI SE) via designing the hierarchical structures for electromagnetic interference (EMI) shielding polymer composites. Among the plentiful structures, the asymmetric structures are currently a hot spot, principally categorizing into multi-layered, porous, fibrous, and segregated asymmetric structures, which endows the high EMI shielding performance for polymer composites incorporated with magnetic, conductive, and/or dielectric micro/nano-fillers, due to the "absorption-reflection-reabsorption" shielding mechanism. Therefore, this review provides the retrospection and summary of the efforts with respect to abundant asymmetric structures and multifunctional micro/nano-fillers for enhancing EMI shielding properties, which is conducive to the booming development of polymeric EMI shielding materials for the promising prospect in modern electronics and 5-generation (5G) technology. [ABSTRACT FROM AUTHOR]

In this study, flexible and highly conductive composite rubber at low filler content was successfully prepared through polydopamine-assisted electroless silver plating plus mechanical mixing. Firstly, carbon fibers (CF) were activated by polydopamine (PDA) to improve the surface activity by self-polymerization reaction. Next, because of the metal chelating ability of PDA, silver layer was firmly deposited on the surface of CF through a facile electroless silver plating method. Finally, flexible silver-plated carbon fibers (Ag/pCF) silicone rubber composites prepared by mechanical mixing. By using X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), the chemical composition and crystal structure of Ag/pCF were examined, and scanning electron microscopy (SEM) was used to assess the surface morphology of the Ag/pCF. The results showed that a uniform and dense silver layer was formed on the surface of the CF, and the conductivity of the Ag/pCF could reach 7885 S/cm. It was noteworthy that the composite rubber filled with only 45 phr Ag/pCF had a high electromagnetic interference shielding effectiveness (100 dB) due to the low density and high aspect ratio of Ag/pCF. The composite rubber has excellent potential for application in the field of electromagnetic interference shielding. [ABSTRACT FROM AUTHOR]

Cu-mesh transparent conductive film offers high conductivity and transparency, making it suitable for electromagnetic interference (EMI) shielding. However, the oxidation of the Cu-mesh transparent conductive film in the atmosphere, limits its use. To solve this problem, the ITO/Cu-mesh transparent conductive film structure is employed to avoid Cu oxidation and improve EMI shielding performance in this study. By stacking the Cu mesh with ITO film, the resistivity and average X-band EMI shielding effectiveness can be improved from 7.89 × 10−7 Ω cm and − 23.4 dB to 7.35 × 10−7 Ω cm and − 25.6 dB, respectively. Additionally, we performed a 72-h salt corrosion test on the samples in accordance with the ASTM B-117 guidelines; the ITO/Cu-mesh film structure does not observe any obvious etching or oxidation. The results show that ITO films are suitable as a protective Cu-mesh coating and confirming that ITO/Cu-meshes have excellent weather resistance and EMI shielding effectiveness. [ABSTRACT FROM AUTHOR]

Increasing dependence and usage of electronic devices has raised the concern for electromagnetic (EM) shielding. This review article is an overview of ongoing cutting-edge research on electromagnetic shielding materials, their applications, advantages and shortcomings. The article highlights doping of polypyrrole(PPy) with different components to achieve desired properties. The work focusses on methods of achieving desired properties of PPy through doping. We have summarized results of doping it with Graphene, Nickel, MXene, Iron Oxide and CNT to achieve desired properties like better electrical conductivity, flexibility and lighter material, greater tensile strength, biocompatibility, better microwave absorption and better magnetic properties. The review presents compilation of most recent ongoing research in the field of electromagnetic shielding. We have also discussed existing limitations and possible future prospects in the ongoing research. [ABSTRACT FROM AUTHOR]

The design of multifunctional materials with good thermophysical and electromagnetic shielding properties is desirable to overcome overheating and electromagnetic interference (EMI) in electronic devices. In this study, three‐dimensional (3D) continuous SiC skeleton‐reinforced highly oriented graphite flake (GF@SiC) composites were fabricated by combining molten salt synthesis, heat treatment, and spark plasma sintering. When the SiC content was higher than 9 vol.%, a 3D continuous SiC skeleton was formed, which effectively constrained the cross‐plane thermal expansion of the GF@SiC composites. Highly oriented GFs endowed the composites with good thermal conductivity (TC) along the basal plane and effective EMI shielding in the X‐band. The composites with SiC concentrations of 9 vol.% exhibited an optimal comprehensive performance with a high TC of 322 W/m/K in the basal plane direction, a low thermal expansion value of 10.5 × 10−6/K in the through‐plane direction, and EMI shielding effectiveness of 36 dB. Our strategy provides a promising and practical approach for realizing graphite‐based composites to meet the current demands for electronic devices. [ABSTRACT FROM AUTHOR]

Aerogels, as kinetic energy absorbing materials, can find crucial applications for safeguarding in transportation, sports, buildings, construction, and aerospace. However, the highly porous structure makes it extremely fragile for endurance usage. In this study, a half‐full filled structure has been proposed, and the concept has been demonstrated based on shear thickening fluid (STF) and chemically vapor deposited carbon nanotube aerogels (CNTAs), in which the outer part of CNTA is filled with STF while the inner core keeping unfilled. Chemical vapor deposition significantly enhances the elasticity and electromagnetic shielding performance of the native CNTA. The half‐full filled aerogels (HFFA) show a 348% increase in energy absorption compared to the CNTA. At the same time, the density, electronic conductivity, and electromagnetic interference shielding effectiveness (EMI SE) of the HFFAs are 0.117 g cm−3, 1213 S m−1, and 69.52 dB (which is a neglectable reduction of 0.63% compared to native CNTA), respectively. The HFFA strategy provides an alternative route to fabricate robust aerogels with a remarkable increase of target properties while maintaining other properties, such as low density, high pore volume, and conductivity, with limited changes. [ABSTRACT FROM AUTHOR]

Magnesium (Mg)-matrix composites have excellent damping and electromagnetic shielding properties. However, the mismatch between their strength and toughness limits their wide application. The aim of this work is to overcome the strength-toughness mismatch by constructing micro- and nanostructures while maintaining the good functional properties of Mg-matrix composites. Electrophoretic deposition (EPD) was used to spread carbon nanotubes (CNTs) out evenly on a Mg foil matrix. After spark plasma sintering (SPS), the grain organisation was refined, and the interlayer bonding was strengthened by hot rolling deformation. Finally, the microstructure, mechanical properties, damping properties, and electromagnetic shielding properties of the composites were analysed. Compared with the pure Mg laminates, the tensile strength and elongation of the CNT/Mg laminates were increased by 6.4% and 108.4%, respectively, with the significant improvement in toughness resulting from the increase in energy required for crack propagation due to the laminate structure. When the total rolling deflection reaches 80%, the interlayer bond strength of the material is significantly increased, the grain is further refined, and the strength and elongation of the composite material reaches the optimum, with the tensile strength reaching 241.70 MPa and the elongation reaching 6.90%. The interlayer interface and grain refinement also affected the damping Mg and electromagnetic shielding effect of the composites. This work provides an experimental idea for the preparation of high-performance structure-function integrated Mg-based materials. [ABSTRACT FROM AUTHOR]

Graphene‐loaded triiron tetraoxide/silicone‐rubber composites containing highly loaded graphene‐loaded Fe3O4 (Fe3O4@RGO) particles were fabricated using static magnetic field‐induced alignment. The Fe3O4@RGO particles were characterized through Fourier transform infrared, x‐ray diffraction, SEM, and XPS analyses. Subsequently, the influence of added material and the strength of the magnetic field on the alignment distribution of the filler were examined through a synergistic combination of SEM and Raman spectroscopy. The electrical conductivity and electromagnetic shielding properties of the composites were assessed. The electrical conductivity of the composites increased with increasing filler addition, the 25 wt% filler mixture had the fastest curing rate and the maximum torque, and the continued increase in filler addition led to the occurrence of many defects. Concurrently, the alignment distribution of the filler progressively enhances with the augmentation of magnetic field strength. The composites synthesized at 180 mT exhibit the most substantial alignment, facilitating the establishment of effective conductive pathways. This results in a notable enhancement in electromagnetic shielding effectiveness, approximately 400% greater than that of pure silicone rubber and around 40% higher than that of non‐aligned composites. This approach introduces a novel concept for shaping the structural design of flexible electromagnetic shielding materials. Highlights: Highly loaded Fe3O4@RGO was prepared by self‐assembly.The continuous phase structure of Fe3O4@RGO oriented was assessed.Fully oriented Fe3O4@RGO promotes the formation of conductive pathways.Fully oriented Fe3O4@RGO reduced the SER by 13% and increased the SEA by 67%. [ABSTRACT FROM AUTHOR]

Due to the quick growth of portable/wearable devices and electronics, the development of high efficiency flexible electromagnetic interference shielding films is a hot research topic. This work discusses the latest advances in flexible carbon‐based electromagnetic interference shielding films, such as constructing desirable structures, combining with magnetic constituents, and filling with polymer matrices. The new construction strategies, preparation methods, performances, and associated mechanisms are summarized. Moreover, the synergism, multifunctionality, and potential application of outstanding carbon‐based electromagnetic interference shielding films including graphene‐based, CNT‐based, and carbon fiber‐based films are analyzed in detail. Additionally, some significant issues and prospective views on carbon‐based composites as flexible electromagnetic interference shielding films are also presented. Highlights: The latest progress of flexible carbon‐based EMI shielding filmsConstructing desirable structure, synergizing with others, designing CPCsThe relationship between preparation, structure, property, and mechanismsThe synergism, multifunctionality, application of EMI shielding filmsKey challenges and future perspectives of carbon‐based EMI shielding films [ABSTRACT FROM AUTHOR]

The present study is investigating the use of short carbon fiber (SCF) and silver‐coated hollow glass microsphere (Ag@HGM) reinforced epoxy light‐weight composites for electromagnetic interference (EMI) shielding applications in the X‐band frequency range (i.e., 8–12 GHz). The study found that Ag@HGM along with SCF significantly improved the dielectric properties of the composites and enhanced the EMI shielding effectiveness of 34.6 dB. Thermal analysis indicates that the sample shows a high rate of heat dissipation and good thermal conductivity. The dynamic mechanical analysis has indicated that the composite has improved storage modulus, glass transition temperature, and activation energy. Highlights: SCF and Ag@HGM epoxy composite is fabricated for EMI shielding application.Two steps: etching and electroless coating of HGM are used for silver coating.The addition of Ag@HGM has enhanced total SE from 27.4 to 34.6 dB.EM wave gets scattered, experiences internal reflections view SCF and Ag@HGM.Additionally, enhancement of thermal and mechanical properties is observed. [ABSTRACT FROM AUTHOR]

Superhydrophobic surfaces are used in fields such as self-cleaning, anti-corrosion and anti-rust, and electromagnetic shielding because they are not wetted by water droplets. We manipulated the scanning spacing and scanning times of the femtosecond laser to control the surface morphology of alumina ceramics, resulting in the creation of two microstructures: micropillars and microhills. Subsequent heat treatment in an oven at 100 °C for 12 h formed a superhydrophobic surface without additional chemical modification, with a contact angle as high as 171.706°. Experimental results show that the superhydrophobicity of the alumina ceramic surface is due to the micro-nano structure of the ceramic surface under specific laser parameters and the hydroxylation of the alumina ceramic itself combined with organic compounds in the air. In addition, the ceramic still has excellent superhydrophobic properties up to 155° after being left in the air for 35 days and abraded by 800-grit sandpaper for 1 m under a pressure of 2.2kpa. Our work uses a new environmentally friendly method to make alumina ceramic surfaces both wear-resistant and superhydrophobic. [ABSTRACT FROM AUTHOR]

Given the escalating prevalence of electromagnetic pollution, there is an urgent need for the development of high‐performance electromagnetic interference (EMI) shielding materials. Herein, wood‐based electromagnetic shielding materials have gained significant popularity due to their exceptional performance as building materials. In this study, a novel wood‐based composite with electromagnetic shielding properties is developed. Through the in situ growth of zeolitic imidazolate framework‐8 (ZIF‐8) crystals on wood fibers, coupled with uniform integration of carbon nanotubes (CNTs), a multifunctional composite named ZIF‐8/Poplar‐CNT composite is synthesized via a one‐step thermoforming process. The incorporation of CNTs endows the composites with excellent EMI shielding effectiveness (EMI SE). Among these elements, despite ZIF‐8 crystals not possessing intrinsic electromagnetic shielding functionality, their distinctive dodecahedral structure proves adept at scattering and reflecting electromagnetic waves within the composites, further improving the electromagnetic shielding effect. Hence, the ZIF‐8/Poplar‐CNT composite (56.95 dB) has ≈10 dB higher EMI SE compared to that of the composites without ZIF‐8 crystals. Meanwhile, ZIF‐8 crystals endow the materials with excellent tensile strength (54.84 MPa, enhanced by 4 times). Moreover, the introduction of Zn2+ provides superior antibacterial properties. The potential applications of ZIF‐8/Poplar‐CNT composites extend to diverse areas such as building decoration, electronic products, and medical equipment. [ABSTRACT FROM AUTHOR]

Metasurfaces with designable electromagnetic parameters are ideal candidates for broadband and tunable microwave absorbers. Water‐based metasurface microwave absorbers have been demonstrated to exhibit ultra‐broadband and near‐unity absorption. However, a broadband microwave absorber with constant and designable efficiencies remains a challenge due to stringent impedance‐matching conditions over a large frequency region. In this work, a design paradigm of microfluidic metasurface absorbers is proposed to regulate absorption efficiency over a wide frequency range. As an example, microfluidic metasurface absorbers are demonstrated with constant absorption efficiency over the Ku band, which is designable from 61.8% to 99.9%. The broadband metasurface absorbers have the advantages of easy fabrication, low cost, and optical transparency, making them highly promising for applications in fields like electromagnetic shielding, active camouflage, electromagnetic pollution control, and wireless communications. [ABSTRACT FROM AUTHOR]

The rapid development of electronic devices in various fields has stimulated an increased demand for electromagnetic interference (EMI) shielding materials working in ultra‐wideband frequencies of gigahertz. However, the aggregation problem and single attenuation mechanism severely limit the broadband shielding applications of nanomaterials. To address these challenges, a novel composite of parallel expanded graphite (EG) embedded in the densified Fe3O4 matrix is designed and successfully synthesized through the in situ chemical coprecipitation followed by pressure sintering. This unique structure creates heterogeneous interfaces by combining the conductive EG and magnetic Fe3O4. The significant dielectric and magnetic loss then arise from conduction and polarization loss, as well as the eddy current and resonance effects. The multiple reflections of electromagnetic waves between the oriented EG sheets further cause the "absorb–reflect–reabsorb" effect that prolongs the propagation paths and enhances the dissipation of electromagnetic waves. Based on these multiple mechanisms over an ultrawide range of frequencies (8.2–40 GHz), the EG/Fe3O4 composites exhibit exceptional EMI shielding performance, with an average shielding effectiveness of 29.3 dB, indicating the potential for multifunctional EMI shielding applications. [ABSTRACT FROM AUTHOR]

As microelectronic technology advances, electronic devices have become faster and smaller. The electromagnetic radiation has negative effects on electronic device operation, how to eliminate the electromagnetic radiation has attracted much attention. Copper foil is the most commonly used and effective material for reducing electromagnetic radiation. In practical applications, it is necessary to use adhesive to fix it onto the surface of electronic devices. In this work, an integrated electromagnetic shielding material (AgPs/TPU@Cu hybrid film) was designed and prepared by a facile way, in which the mixture of silver particles (AgPs) and thermoplastic polyurethane (TPU) was cured to form a AgPs/TPU composite film on the surface of copper foil (Cu) by a one-pot heating press processing. The horizontal and vertical electrical resistances of AgPs/TPU composite film decreased to 0.2 Ω and 0.47 Ω at the AgPs loading of 38 wt%, respectively, and the corresponding thermal conductivity reached 0.81 W m−1 K−1. Moreover, the AgPs/TPU@Cu hybrid film at the AgPs loading of 38 wt% exhibited the maximum electromagnetic interference shielding effectiveness (EMI SE) value of 105 dB. This work provides valuable information about EMI shielding technologies for practical electronic applications. [ABSTRACT FROM AUTHOR]

Currently, Electromagnetic (EM) pollution is harmful to human health because of the generation and propagation of high-frequency EM waves from electronic devices. The absorbing materials with outstanding properties are highly desirable. Meta-absorbers with extraordinary electromagnetic wave absorption, outstanding EM shielding ability, and featured dissipation efficiency are still worth challenging in the surrounding environments. The meta-absorbers were fabricated, designed, and simulated to address the challenges. Nd–Co co-doped Co–Zn spinel nano ferrites (Co 0.5 Zn 0.5-x Cu x Fe 2-y Nd y O 4 with x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, y = 0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were prepared. XRD, FESEM, FTIR, and VSM were used to study the structure, phase, vibrational, elastic, and magnetic features of the Nd–Co co-doped Co–Zn ferrites, respectively. Rietveld refinement of the Nd–Co co-doped Co–Zn ferrites was evaluated by FullProf software. Wyckoff locations and occupancy of the already present cations and anions were refined. The bond lengths and unshared-shared edges were determined using the Bertaut method. The detailed phase occurrence, force constant, and elastic features of Nd–Co co-doped Co–Zn ferrites were also investigated. The mixed shapes of grains like elliptical, circular, and hexagons were noticed from FESEM images. The magnetization and coercivity were reduced with the Nd–Cu doping. Switching field and high-frequency response were also presented for the Nd–Cu co-doped Co–Zn ferrite. The dielectric properties like complex permittivity and permeability depicted higher response at high frequency due to interfacial polarization in prepared ferrites. The reflection loss (RL) of −74.1 dB was noticed at 1.99 GHz for x = 0.4, y = 0.08. However, the reflection loss of −63.9 dB at 2.24 GHz was observed for x = 0.5, y = 0.1. Meta-absorbers of Nd–Cu co-doped NiZn were designed and simulated. The wideband absorptivity is depicted for Nd–Cu co-doped CoZn ferrite as substrate material at x = 0.0 y = 0.00, x = 0.1 y = 0.02, and the absorptivity remains highest for θ = 0 deg. The absorptivity significantly reduces with the increase of incidence angle. Meta-absorbers based on Nd–Cu co-doped Co–Zn ferrites are good future candidates for EMI (electromagnetic interference), MLCIs (multilayer chip inductors), electromagnetic shielding, and 5G-mobile antenna purposes in high-frequency applications. [ABSTRACT FROM AUTHOR]

Widespread integration of carbon‐based membranes into prevailing fields like energy storage and material engineering is thwarted by a lack of functionality, customization, and compatibility, making the development of such carbon‐based membranes urgency yet challenging. Herein, a "graphene bubble bridging" strategy is adopted to fabricate the multifunctional carbon fiber membrane, in which graphene bubbles with optimized assembling not only endow the carbon fiber with superior flexibility and integrity by embedded bridging function, but also enhance the fast electron transport capability and electrolyte wettability. Few‐layer MoSSe nanosheets with expanded interlayer spacing as a typical energy storage material contribute to plentiful ion intercalation/deintercalation that can be well buffered within the robust fibers. The interlaced carbon fibers enable a self‐supporting framework that ensures good conductivity and mechanical stability as well. Such functional, customized, and compatible membranes with synergies can boost the attributes of advanced K+ storage devices, such as flexible K‐ion capacitors and K‐based dual‐ion batteries. This work can afford new insights for designing flexible electrode in the energy storage field, as well as various types of conformations that can bring more opportunities on developing flexible functional membranes for other fields (e.g., catalysts, electromagnetic shielding). [ABSTRACT FROM AUTHOR]

Composite polymer materials featured superior thermal conductivity, flame retardancy, and electromagnetic shielding performance are increasingly in demand due to the rapid development of highly miniaturized, portable, and flexible electronic devices. Herein, a facile and green ball milling shear method is utilized for generating MXene@Boron nitride (MXene@BN). The multi‐functional fillers (MXene@BN) are constructed and incorporated into polydimethylsiloxane (PDMS) to prepare a multifunctional composite (PDMS/MXene@BN) for achieving improved electromagnetic interference (EMI) shielding performance and thermal conductivity as well as flame retardancy simultaneously. When the PDMS/MXene@BN composite has a MXene@BN loading of 2.4 wt.%, it exhibits a high thermal conductivity of 0.59 W m−1K−1, which is 210% higher than that of the pure PDMS matrix. This is attributed to its unique chestnut‐like double‐layer structure. With a smoke production rate (SPR) of 0.04 m2 s−1 and total smoke production (TSP) of 3.51 m2, PDMS/MXene@BN 2.4 composite exhibits superb smoke suppression properties. These SPR and TSP values are 63.20% and 63.50% lower than the corresponding values of pure PDMS. Moreover, the EMI SE of the PDMS/MXene@BN 2.4 can reach 26.3 dB at 8.5 GHz. The work reported herein provides valuable insight into developing composites with multiple functions, which show strong potential for application in advanced packaging materials. [ABSTRACT FROM AUTHOR]

This paper presents the obtaining and characterization of recycled polypropylene/strontium ferrite (PP/SrFe12O19) polymer composite materials with applications in the electromagnetic shielding of vehicle interiors (mainly automotive electronics—carcasses) from the electromagnetic radiation emitted mainly by exterior sources—electrical lines and supply sources—in terms of the development of the new electrical vehicles. With this aim, suitable polymer composite materials were developed using SrFe12O19 filler in two forms (powder and concentrate). The recycled PP polymer and composite materials with a PP/SrFe12O19 weight ratio of 75/25 and 70/30 were obtained in two stages, i.e., pellets by extrusion and samples for testing through a melt injection process. The characterization of the obtained materials took into account the requirements imposed by the desired applications. It consisted of determining the mechanical and dielectric properties, and microstructure analyses, along with the determination of the resistance to the action of a temperature of 70 °C, which is higher than the temperatures created during the summer inside vehicles. The performance of these materials as electromagnetic shields was assessed through functional tests consisting of the determination of magnetic permeability and the estimation of the electromagnetic shielding efficiency (SE). The obtained results confirmed the improvement of the mechanical, dielectric, and magnetic properties of the PP/SrFe12O19 composites compared to the selected PP polymers. It is also found that all the composite materials exhibited reflective shielding properties (SER from −71.5 dB to −56.7 dB), with very little absorption shielding. The most performant material was the composite made of PP/SrFe12O19 powder with a weight ratio of 70/30. The promising results recommend this composite material for potential use in automotive shielding applications against electromagnetic pollution. [ABSTRACT FROM AUTHOR]

Graphene nanoplatelets (GNPs)/epoxy composites have been fabricated via gravity molding. The electrical and thermal properties of the composites have been studied with variable GNP type (C300, C500, and C750, whose surface areas are ~300, 500, and 750 m2/g, respectively), GNP loading (5, 10, 12, and 15 wt.%), and dispersion time via ultrasonication (0, 30, 60, and 120 min). By increasing the time of sonication of the GNP into the epoxy matrix, the electrical conductivity decreases, which is an effect of GNP fragmentation. The best results were observed with 10–12% loading and a higher surface area (C750), as they provide higher electrical conductivity, thereby preserving thermal conductivity. The influence of sonication over electrical conductivity was further analyzed via the study of the composite morphology by means of Raman spectroscopy and X-ray diffraction (XRD), providing information about the aspect ratio of GNPs. Moreover, electromagnetic shielding (EMI) has been studied up to 4 GHz. Composites with C750 and 120 min ultrasonication show the best performance in EMI shielding, influenced by their higher electrical conductivity. [ABSTRACT FROM AUTHOR]

Flexible piezoresistive sensors hold great promise in biomedicine and personal motion detection, attracting significant attention from researchers. Particularly, two‐dimensional (2D) MXene has made remarkable strides in biomedicine, electromagnetic shielding, and other practical applications, due to its exceptional hydrophilicity, biocompatibility, mechanical properties, surface functional groups, and large specific surface area. The ease of composite material formation further makes it ideal for high‐sensitivity flexible sensors. This paper summarizes the principal structural configurations for the multi‐scale interfaces, performance assessment metrics, and the corresponding sensing mechanisms of flexible piezoresistive sensors. Subsequently, the main characteristics and synthesis methods of MXene, especially the related applications and parameters are introduced in detail. The research trends and typical applications of MXene‐based flexible piezoresistive sensors focused on film structures, fiber structures, 3D structures, and hydrogel structures, are highlighted systematically. In addition, the challenges and prospects that promoting the advancement of MXene‐based flexible piezoresistive sensors in future are also discussed, which will revolutionize the sensing field and offer a wealth of opportunities in biomedicine and beyond. [ABSTRACT FROM AUTHOR]

Pristine polyaniline and polyaniline/iron oxide-based nanocomposites with efficient microwave shielding properties have been synthesized by in-situ polymerization route. The morphological and molecular bonding properties of prepared samples have been examined using Field emission scanning electron microscope (FESEM) and Fourier transform infrared (FTIR) spectroscopy techniques, respectively. FESEM studies reveal the formation of 100–500 nm size agglomerates of polyaniline (PANI) and its nanocomposites with Fe3O4. FTIR spectroscopy endorses the synthesis of desired materials through the presence of required fundamental bands. Moreover, the increase in electrical conductivity with Fe3O4 can be analyzed through the enhancement in area under the curve of –NH+= band. The electromagnetic interference (EMI) shielding properties of synthesized materials have been investigated in X-band region (8.2–12.4 GHz) of electromagnetic radiations. The total EMI blocking efficiency for pristine PANI sample is found to be ~ 31 dB, and the blocking efficiency of PANI is found to be further improved with the embedment of Fe3O4 nanoparticles in different concentrations. The synthesized materials are well-matched with the standards of industrial requirements in terms of shielding efficiency (i.e., > 30 dB), light weight and attenuation ability (> 99%). [ABSTRACT FROM AUTHOR]

Mechanical and electromagnetic interference (EMI) shielding properties are investigated for developed synthesized green composite. The varying content of kenaf fiber‐reinforced high‐density polyethylene (HDPE) composite has been fabricated using microwave‐assisted compression molding techniques with and without the addition of multi‐walled carbon nanotubes (MWCNTs). X band range has been used for EMI shielding characterization. Optimization for mechanical strength has been done using tensile test, impact test, and translaminar fracture toughness test. Fractography by scanning electron and optical microscopy concluded that interfacial adhesion between kenaf fiber and HDPE matrix and the degree of ductility of the matrix are primary governing factors for change in mechanical properties. The differential scanning calorimetry confirmed no change in the degree of crystallization of the matrix with the addition of MWCNTs. Composite with EMI shielding effect above 30 dB along with superior mechanical properties is obtained at 16% (v/v) kenaf fiber content with the addition of 5% (wt.) conductive MWCNTs for possible application in electronic equipment casing, overhead bin, or unmanned aerial vehicles. [ABSTRACT FROM AUTHOR]

Highlights: The composite films are composed of hollow metal–organic frameworks/layered MXene/nanocellulose with unique alternating electromagnetic structures. The optimized composite films exhibit excellent EMI shielding performance of 66.8 dB at GHz frequency and 114.6 dB at THz frequency. The EMI shielding ability of composite films to electromagnetic waves is verified by practical visualized application simulation. The composite films show remarkable photothermal conversion performance, which can reach 235.4 °C under 0.8 W cm−2. With the continuous advancement of communication technology, the escalating demand for electromagnetic shielding interference (EMI) materials with multifunctional and wideband EMI performance has become urgent. Controlling the electrical and magnetic components and designing the EMI material structure have attracted extensive interest, but remain a huge challenge. Herein, we reported the alternating electromagnetic structure composite films composed of hollow metal–organic frameworks/layered MXene/nanocellulose (HMN) by alternating vacuum-assisted filtration process. The HMN composite films exhibit excellent EMI shielding effectiveness performance in the GHz frequency (66.8 dB at Ka-band) and THz frequency (114.6 dB at 0.1–4.0 THz). Besides, the HMN composite films also exhibit a high reflection loss of 39.7 dB at 0.7 THz with an effective absorption bandwidth up to 2.1 THz. Moreover, HMN composite films show remarkable photothermal conversion performance, which can reach 104.6 °C under 2.0 Sun and 235.4 °C under 0.8 W cm−2, respectively. The unique micro- and macro-structural design structures will absorb more incident electromagnetic waves via interfacial polarization/multiple scattering and produce more heat energy via the local surface plasmon resonance effect. These features make the HMN composite film a promising candidate for advanced EMI devices for future 6G communication and the protection of electronic equipment in cold environments. [ABSTRACT FROM AUTHOR]

Biological macroporous materials, such as stems of the plants and bone of the animals, possess outstanding properties for powerful guarantee of creatures' survival through the well‐aligned architecture constructed from limited components. Transition metal carbides or nitrides (MXenes), as novel 2D assemblies, have attracted numerous attentions in various applications due to their unique properties. Therefore, mimicking the bioinspired architecture with MXenes will boost the development of human‐made materials with unparalleled properties. Freeze casting has been widely applied to fabricate bioinspired MXene‐based materials and achieve the assembly of MXene nanosheets into 3D forms. This process solves the inherent restacking problems of MXenes, simultaneously preserving the unique properties of MXenes with a physical process. Here, the ice‐templated assembly of MXene in terms of the freezing processes and their potential mechanisms is summarized. In addition, applications of MXene‐based materials in electromagnetic interference shielding and absorption, energy storage and conversion, as well as piezoresistive pressure sensors are also reviewed. Finally, the current challenges and bottlenecks of ice‐templated assembly of MXene are further discussed to guide the development of bioinspired MXene‐based materials. [ABSTRACT FROM AUTHOR]

The colossal development of modern electronic devices has inevitably led to an increase in electromagnetic interference (EMI), which has gradually become the fourth most prevalent type of pollution in the world. It is therefore necessary to seek more effective EMI‐shielding materials to overcome the shortcomings of conventional metal‐based materials, which include high density, a lack of mechanical flexibility, low corrosion resistance and costly processing. Conductive polymer composites (CPCs) have attracted more and more attention due to their superiority in many aspects. However, their performances should be further enhanced for future applications. One polymer with only one type of filler often cannot meet this kind of requirement. In this paper, filled polymer materials for EMI shielding are reviewed in terms of their processing, rheological properties, conductivity, and shielding effectiveness. Moreover, the combination of different ingredients and fillers when fabricating multicomponent composites for EMI shielding is also highlighted. The coordination of various components in composites with different structures, including solid, segregated, layered/sandwiched, and foamed/porous structures, is then discussed. [ABSTRACT FROM AUTHOR]

This study aims to convert composite textile structures composed of nonwoven and woven fabrics produced from cotton–jute wastes into activated carbon textile structures and investigate the possibilities of using them for electromagnetic shielding applications. To this end, the novel contribution of this study is that it shows that directly carbonized nonwoven textile via self-purging microwave pyrolysis can provide Electromagnetic Interference (EMI) shielding without any processing, including cleaning. Textile carbonization is generally achieved with conventional heating methods, using inert gas and long processing times. In the present study, nonwoven fabric from cotton–jute waste was converted into an activated carbon textile structure in a shorter time via microwaves without inert gas. Due to its polar structure, FeCl3 has been used as a microwave absorbent, providing homogeneous heating in the microwave and acting as an activating agent to serve dual purposes in the carbonization process. The maximum surface area (789.9 m2/g) was obtained for 5% FeCl3. The carbonized composite textile structure has a maximum of 39.4 dB at 1 GHz of EMI shielding effectiveness for 10% FeCl3, which corresponds to an excellent grade for general use and a moderate grade for professional use, exceeding the acceptable range for industrial and commercial applications of 20 dB, according to FTTS-FA-003. [ABSTRACT FROM AUTHOR]

Highlights: A stretchable, transparent, and ultra-broadband (0.1–10 THz) terahertz shielding MXene (Ti3C2Tx) film has been fabricated by a structure engineering strategy. Theoretical calculations indicate that the wrinkled structure enhances the film's conductivity and surface plasmon resonances, resulting in an improved THz wave absorption. The wrinkled MXene films exhibit superb conformability to surfaces with random curvatures, and can be used as a shielding film for THz imaging. With the increasing demand for terahertz (THz) technology in security inspection, medical imaging, and flexible electronics, there is a significant need for stretchable and transparent THz electromagnetic interference (EMI) shielding materials. Existing EMI shielding materials, like opaque metals and carbon-based films, face challenges in achieving both high transparency and high shielding efficiency (SE). Here, a wrinkled structure strategy was proposed to construct ultra-thin, stretchable, and transparent terahertz shielding MXene films, which possesses both isotropous wrinkles (height about 50 nm) and periodic wrinkles (height about 500 nm). Compared to flat film, the wrinkled MXene film (8 nm) demonstrates a remarkable 36.5% increase in SE within the THz band. The wrinkled MXene film exhibits an EMI SE of 21.1 dB at the thickness of 100 nm, and an average EMI SE/t of 700 dB μm−1 over the 0.1–10 THz. Theoretical calculations suggest that the wrinkled structure enhances the film's conductivity and surface plasmon resonances, resulting in an improved THz wave absorption. Additionally, the wrinkled structure enhances the MXene films' stretchability and stability. After bending and stretching (at 30% strain) cycles, the average THz transmittance of the wrinkled film is only 0.5% and 2.4%, respectively. The outstanding performances of the wrinkled MXene film make it a promising THz electromagnetic shielding materials for future smart windows and wearable electronics. [ABSTRACT FROM AUTHOR]

The electromagnetic pollution problem is becoming increasingly serious due to the speedy advance of electronic communication devices. There are broad application prospects for the development of flexible, wearable composite films with high electromagnetic interference (EMI)-shielding performance. The MX@AC composite films were prepared from MXene, silver nanowires (AgNWs) and cellulose nanocrystals (CNCs) with a sandwich structure. Benefiting from the upper and lower frame structure formed by winding 1D AgNWs and CNC, the tensile strength of the MX@AC was improved to 35 MPa (12.5 wt% CNC content) from 4 MPa (0 wt% CNC content). The high conductivity of MXene and AgNWs resulted in the MX@AC composite film conductivity up to 90,670 S/m, EMI SE for 90 dB, as well as SSE/t up to 7797 dB cm2 g−1. And the MX@AC composite film was tested for practical application, showing that it can effectively isolate electromagnetic waves in practical application. [ABSTRACT FROM AUTHOR]

Optically transparent polycarbonates (PCs) and Copoly(Imide-Carbonate)s (Co-PICs) were synthesized by the melt polycondenzation method. Rigid (imide) and flexible (-O- and –C(CH3)2−) moieties were incorporated in the structure of bisimide diol comonomer using 4-aminophenol and 4,4′-(4,4′-isopropylidenediphenoxy) bis(phthalic anhydride). The structural properties of synthesized comonomers and polymers were confirmed by 1H, 13C-NMR and FT-IR spectra. Thermal properties of polycarbonates and copolycarbonates were examined using DSC and TG analysis. Thermal properties (glass transition T g and thermal decomposition (Td) temperature) of copolymers were enhanced without sacrificing properties of BPA-based PC (high transparency, ductility, and processability) by the incorporation of active functional bisimide diol comonomer (5–10 mole %) in the polycarbonate backbone. Different sets of PCs and Co-PICs thin film substrates were prepared by the solvent casting method and used to design frequency selective surface. The proposed flexible FSS offers shielding of 20 dB at 8.8 GHz. In addition, the FSS offers polarization independent operation with its symmetrical unit cell geometry. [ABSTRACT FROM AUTHOR]

Materials with characteristics of omnidirectional reflectionless absorption are of great importance in electromagnetic shielding and anechoic chamber. Recently emerged absorbing surfaces mostly work at a given angle, and absorbers working at a broad frequency band usually suffer from a 3-D structure. Thus, the fabrication of the ultra-thin and omnidirectional reflectionless absorber working at dual-frequency remains a technical challenge. In this work, we demonstrated the absorbing performance of an ultra-thin slab under different incident angles of the electric fields, and an approximate solution was derived to prove the realizability of the dual-frequency and omnidirectional reflectionless absorption. For illustration, a miniaturized dual-frequency anechoic chamber with a 343.8 mm diameter was constructed, and the full-wave simulations validated the results. The proposed design method is simple and robust, which provides a new clue for solving the practicability difficulty faced by existing anechoic chambers and microwave imaging systems. [ABSTRACT FROM AUTHOR]

Summary: A novel band‐stop frequency‐selective surface (FSS) for X‐band electromagnetic shielding is reported in this study. The single‐layer, single‐sided FSS has frequency‐dependent conductive patterns developed on a polyimide substrate that provides strong rejection to the entire X‐band frequencies. The unit cell FSS has an octagonal loop configuration. Each side of the octagonal loop is alternatively loaded with thick conductive patches and stub lines to reject 8 − 12 GHz with |S21| ≤ −15 dB. The size of the unit cell FSS is 0.167λo × 0.1673λo where λo is the free space wavelength calculated at the center frequency. Owing to the rotational symmetry, the FSS unit cell exhibits mode‐independent characteristics. The bending characteristics of the FSS are analyzed, and the inferences show that the FSS properties remain unchanged under flat and bent cases. The ultra‐thin FSS offers stable frequency response for normal and oblique incidences up to 80°. The designed FSS is fabricated and tested under laboratory conditions to validate the simulation results. [ABSTRACT FROM AUTHOR]

Conductive polymer composites require high conductive filler loadings to achieve relatively ideal electromagnetic interference (EMI) shielding performance, which brings problems such as heavy weight and poor processability and ultimately limits their application in the aerospace field. To solve the above problems and realize the preparation of excellent EMI shielding composites with low filler loadings, a bipolar pulsed electric field-induced graphene nanoplatelets (GNPs) alignment method is proposed in this paper to improve the electrical conductivity and EMI shielding performance. The orientation and alignment of GNPs in the matrix were characterized by x-ray diffraction and scanning electron microscopy, and the results showed that GNPs formed a conductive network. The electrical conductivity of the composite material in the X-band was measured, and the results showed that the bipolar pulsed electric field could significantly improve the electrical conductivity of the composite material; the improvement percentage reached 100%–300% under the five filler loadings. In addition, the EMI shielding effectiveness of the composite material in the X-band was tested. The results showed that the EMI shielding effectiveness of the composite material with a mass fraction of 14% increased from 16.48–15.86 dB to 21.37–20.99 dB with the action of the bipolar pulsed electric field, and the improvement percentage was 32%. This is the first study on improving the EMI shielding performance of composite materials by applying a bipolar pulsed electric field, and it provides an effective method to prepare EMI shielding composites with low filler loadings. [ABSTRACT FROM AUTHOR]

Electromagnetic pollution has increased because of technological advances and the use of telecommunication equipment and electronics. Developing a smart shielder based on nanocomposite polymer with excellent electromagnetic radiation shielding (EMS) is highly desired for protection. This review will cover the challenge of reducing electromagnetic radiation by developing smart nanocomposite polymers with a broad absorption frequency. The study will focus on the impact of electromagnetic radiation on our natural surroundings. The reflection, absorption, and multiple reflection EMS strategies will also be covered. The fabrication methods of nanocomposite polymer will be investigated. Finally, future perspectives and research routes will be considered. [ABSTRACT FROM AUTHOR]

Technological advances have accelerated the pursuit of transparent conducting thin films (TCFs) with superior mechanical properties, durability, efficient optoelectrical performance and substrate compatibility as a pivotal focus in the realm of flexible transparent electronics. Against this background, this work investigates the fabrication of multilayer silver nanowire (AgNW) thin films reinforced by zinc tin oxide (ZTO) thin film encapsulation on polycarbonate substrates by a combination of sputtering and spin-coating techniques. An investigation of the influence of AgNW percolation networks on the optoelectrical properties of ZTO/AgNW/ZTO hybrid thin films was carried out. The impact of ZTO protective layers on the enhancement of electrical properties, adhesivity, flexibility and environmental stability of the multilayer TCF was elucidated. Additionally, to explore the compatibility of the fabricated TCF in integrated device and stealth applications, its electromagnetic interference shielding properties were investigated. The hybrid TCF showed 99.47% EMI shielding efficiency with an absorption-dominant EMI shielding effectiveness of 22.7 dB in the x-band region. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multi-interfacial bridging engineering was used to prepare the flexible MXene film. • Highly efficient electromagnetic shielding capability is achieved through a dense multiple conductive network. • The total EMI shielding effectiveness can be increased by 27 % with the highest value of 67.9 dB. • The infrared emissivity is as low as 0.173 within the 8–14 μm. • The mechanism of the shielding and photothermal compatibility along with the durability are proposed. Accompanied by the progressive development of electronic equipment, excellent electromagnetic interference (EMI) shielding materials display a satisfying prospect in protecting electronic devices against electromagnetic pollution/radiation, while integrating energy conversion. Heretofore, it remains a conundrum to availably construct thin films with multi-interfacial bridging engineering as multifunctional shielding devices. To effectively achieve electromagnetic wave attenuation and integrate energy conversion, a co-mixed vacuum-assisted filtration strategy is designed to synthesize Au@MXene/cellulose nanocrystal/dodecylbenzenesulfonic acid-doped polyaniline (AMCP) films. Profited from the interfacial engineering, the total EMI shielding effectiveness (SE) can be increased by 27 % with the highest value of 67.9 dB. MXene with localized surface plasmon resonance characteristics gives the composite films good energy conversion performance, that is, the composite film can be rapidly heated up to 100 °C under the irradiation of an infrared lamp, and its surface temperature remains stable after continuous irradiation. Additionally, the infrared emissivity is as low as 0.173 within the 8–14 μm, which is necessary to adapt various application scenarios. Therefore, it is reliable that the AMCP films constructed by multicomponent offer a facile strategy for MXene-based EMI shielding devices with integration characteristics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Surface modification of PET substrates using polyvinylpyrrolidone to improve substrate hydrophilicity. • The MXene/AgNW/MXene transparent conductive films with a sandwich structure were prepared by layer-by-layer self-assembly. • The EMI SE of the MAM TCF achieves 27.12 dB, and the transmittance is 85.1 %. • The MAM TCF has a fast thermal response and high electro-thermal conversion at low voltages. With the popularization of 5G technology and the development of science and technology, flexible and transparent conductive films (TCF) are increasingly used in the preparation of optoelectronic devices such as electromagnetic shielding devices, transparent flexible heaters, and solar cells. Silver nanowires (AgNW) are considered the best material for replacing indium tin oxide to prepare TCFs due to their excellent comprehensive properties. However, the loose overlap between AgNWs is a significant reason for the high resistance. This article investigates a sandwich structured conductive network composed of AgNW and Ti 3 C 2 T x MXene for high-performance EMI shielding and transparent electrical heaters. Polyethylene pyrrolidone (PVP) solution was used to hydrophilic modify PET substrate, and then MXene, AgNW, and MXene were assembled layer by layer using spin coating method to form a TCF with a sandwich structure. One-dimensional AgNW is used to provide electron transfer channels and improve light penetration, while two-dimensional MXene nanosheets are used for welding AgNWs and adding additional conductive channels. The flexible TCF has excellent transmittance (85.1 % at 550 nm) and EMI shielding efficiency (27.1 dB). At the voltage of 5 V, the TCF used as a heater can reach 85.6 °C. This work offers an innovative approach to creating TCFs for the future generation. [ABSTRACT FROM AUTHOR]

Electromagnetic interference (EMI) shielding fabrics are crucial in addressing the increasingly serious electromagnetic pollution. To meet wearable requirements, stretchability and thermal comfortability are often desired, but which still are challenging. Herein, a stretchable EMI shielding fabric is fabricated via electrospinning coupled with biaxial pre‐stretching spraying, in which a block stacking wrinkled silver nanowire (AgNW)/Ti3C2Tx MXene network is coated on one side of electrospun thermoplastic polyurethane (TPU)/polydimethylsiloxane (PDMS) fabric. As expected, the wrinkled structure protects conductive network from fracture during stretching process, so as to realize the strain‐invariant electrical conductivity. Thus, the fabric exhibits a stretchable EMI shielding performance of over 40 dB when subjected to 10–50% uniaxial strains or 21–125% biaxial strains. More importantly, the white TPU/PDMS side and the black AgNW/MXene side enable the fabric passive radiative cooling and heating, respectively. The cooling side exhibits high mid‐infrared emissivity (97.5%) and solar reflectance (90%), thus reducing the skin temperature by ≈4.9 °C. The heating side with high solar absorptivity (86.6%) and photothermal effect increased the skin temperature by ≈5 °C. Therefore, the fabirc with stretchable EMI shielding and Janus‐type dual‐mode personal passive thermal management is promising in future wearable products. [ABSTRACT FROM AUTHOR]

Advances in mobile electronics and telecommunication systems along with 5G technologies have been escalating the electromagnetic interference (EMI) problem in recent years. Graphene-based material systems such as pristine graphene, graphene-polymer composites and other graphene-containing candidates have been shown to provide adequate EMI shielding performance. Besides achieving the needed shielding effectiveness (SE), the method of applying the candidate shielding material onto the object in need of protection is of enormous importance due to considerations of ease of application, reduced logistics and infrastructure, rapid prototyping and throughput, versatility to handle both rigid and flexible substrates and cost. Printing readily meets all these criteria and here we demonstrate plasma jet printing of thin films of graphene and its composite with copper to meet the EMI shielding needs. SE over 30 dB is achieved, which represents blocking over 99.9% of the incoming radiation. Graphene and its composite with copper yield higher green index compared to pure copper shields, implying reduced reflection of incoming electromagnetic waves to help reduce secondary pollution. [ABSTRACT FROM AUTHOR]

The inherent π–π interfacial interaction between carbon nanotubes (CNTs) and polystyrene (PS) makes the CNT/PS composite a representative thermoplastic nanocomposite. However, the strong van der Waals force among CNTs poses challenges to achieving effective dispersion. This review provides an overview of various CNT functionalization methods for CNT/PS composites, encompassing covalent grafting with PS-related polymers and non-covalent modification. A focus in this section involves the pre-introduction surface modification of CNTs with PS or PS-related polymers, substantially enhancing both CNT dispersibility and interfacial compatibility within the PS matrix. Furthermore, a comprehensive summary of the mechanical, electrical, thermal, and electromagnetic shielding properties of CNT/PS nanocomposites is provided, offering an overall understanding of this material. The surface modification methods of CNTs reviewed in this paper can be extended to carbon material/aromatic polymer composites, assisting researchers in customizing the optimal surface modification methods for CNTs, maximizing their dispersibility, and fully unleashing the various properties of CNTs/polymer composites. Additionally, high-performance CNTs/PS composites prepared using appropriate CNT modification methods have potential applications in areas such as electronic devices, sensors, and energy storage and conversion. [ABSTRACT FROM AUTHOR]

A thin, lightweight and flexible electromagnetic interference (EMI) shielding paper composite is an urgent need for modern military confrontations. Herein, a sandwich-structured EMI shielding paper composite with an easy pavement consisting of a filter paper layer, middle AgNWs/MXene layer, and polyvinyl butyral (PVB) layer was constructed by vacuum-assisted filtration, spraying and air-drying. The middle AgNWs/MXene compound endowed the filter paper with excellent electrical conductivity (166 S cm−1) and the fabricated filter paper–AgNWs/MXene–PVB composite exhibits superior EMI shielding (30 dB) with a 141 μm thickness. Remarkably, the specific EMI shielding effectiveness (SSE/t) of the filter paper–AgNWs/MXene–PVB composite reached 13,000 dB cm2 g−1 within the X-band frequency range. This value represents one of the highest reported for cellulose-based EMI shielding materials. Therefore, our sandwich-structured filter paper composite with superior EMI shielding performance can be used in the medical and military fields. [ABSTRACT FROM AUTHOR]

Considering the magnetic shielding requirements of both geomagnetic field and 50 Hz power-line frequency in the complex working conditions of the power grid, an electromagnetic shielding system combining active and passive modes is proposed in this article. A three-dimensional Helmholtz coil with a magnetic shielding barrel nested inside is established by the COMSOL simulation tool, and the magnetic shielding efficiency of the system is analyzed. Comparing different materials, the simulation results indicate that permalloy alloy exhibits better shielding performance than pure iron and nickel materials. Additionally, the overall shielding efficiency of the shielding barrel increases linearly with the number of multiple layers. Under the combined active and passive electromagnetic shielding conditions, the system achieves a shielding efficiency of SE = 113.98 dB, demonstrating excellent performance in shielding both AC and DC interference magnetic fields. This study provides theoretical guidance for the construction of magnetic shielding systems in electromagnetic interference environment. [ABSTRACT FROM AUTHOR]

As the lightest structural metal material, magnesium alloys possess good casting properties, high electrical and thermal conductivity, high electromagnetic shielding, and excellent damping properties. With the increasing demand for lightweight, high-strength, and high-damping structural materials in aviation, automobiles, rail transit, and other industries with serious vibration and noise, damping magnesium alloy materials are becoming one of the important development directions of magnesium alloys. A comprehensive review of the progress in this field is conducive to the development of damping magnesium alloys. This review not only looks back on the traditional damping magnesium alloys represented by Mg-Zr alloys, Mg-Cu-Mn alloys, etc. but also introduces the new damping magnesium materials, such as magnesium matrix composites and porous magnesium. But up to now, there have still been some problems in the research of damping magnesium materials. The effect of spiral dislocation on damping is still unknown and needs to be studied; the contradiction between damping performance and mechanical properties still lacks a good balance method. In the future, the introduction of more diversified damping regulating methods, such as adding other elements and reinforcements, optimizing the manufacturing method of damping magnesium alloy, etc., to solve these issues, will be the development trend of damping magnesium materials. [ABSTRACT FROM AUTHOR]

Long‐time indoor exposure to electromagnetic waves generated by electronic devices has posed a threat to the health of young life. The threat may intensify in low‐temperature environments due to low immunity. Prolific endeavors have focused on developing electromagnetic interference (EMI) shielding materials but failed to meet the visible, portable, and temperature‐controllable indoor‐use requirements. Herein, a detachable and heatable AgNWs/PU composite film is fabricated by facile spray coating and quick melting. The half‐inserted 3D network structure of AgNWs on PU ensures stable and high conductivity, thus endowing sufficient EMI shielding performance at 27 dB for indoor use. The high transparency (≥73.2%) and strong electrostatic force enable the detachable and portable use of the composite film. The resulting Joule heat at the voltage of 5 V endows a heatable property, which raises to 44.8 °C within 60 s. The AgNWs/PU composite film can self‐adhere in an indoor protective chamber, enabling visual monitoring and blocking electromagnetic radiation while keeping a comfortable inside temperature. The facile fabrication makes the self‐adhesive and multifunctional film possible in large‐scale production for practical application. [ABSTRACT FROM AUTHOR]