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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]

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.

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]

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]

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]

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]

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]

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]

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]

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]

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]

In recent years, there has been growing demand for processes to form electromagnetic shielding films on the periphery of semiconductor packages, and shielding films are increasingly being formed by sputter deposition methods with stable processes. However, little consideration has been given to the adhesion mechanism between the mold resin and sputtered Cu film formed on the semiconductor devices. In this study, Cu films were sputtered on mold resin with different etching conditions, and X-ray photoelectron spectroscopy was used to analyze the state of the interface, which affects adhesion. The color difference of the mold resin surface under different Ar and N2 etching conditions was also evaluated. Excellent adhesion between the mold resin and sputtered Cu was achieved under a high flow rate for Ar + N2 etching. The amount of Si (SiO2) exposed on the mold resin surface was correlated with the color difference. We proposed a mechanism in which amino groups in particular were formed on the surface of the mold resin, the resin etching rate increased, and the amount of SiO2 exposed increased. Functional groups, especially amino groups, were also formed on the SiO2 surface by N2 plasma. Cuσ+ in the sputtered film and Nσ- formed on the SiO2 surface adhered to each other through polar interactions. [ABSTRACT FROM AUTHOR]

Poly(3,4‐ethylenedioxythiophene):poly(4‐styrenesulfonate) (PEDOT:PSS) aerogel has attracted much attention in bioelectronics, electromagnetic shielding, and energy‐related systems due to its biocompatibility, intrinsic electronic conductivity, and favorable processability. However, fabrication of highly conductive and low‐density PEDOT:PSS aerogels is still challenging. In this work, highly conductive PEDOT:PSS aerogels are produced via ice‐templated pre‐assembly followed by a specially designed thawing process in H2SO4 solution. Upon optimization of heat and mass transfer during the thawing process, along with the unique ice template effect, the microstructure and thin walls of PEDOT:PSS frozen samples are well preserved. Importantly, the porous structure and thin walls facilitate diffusion of H2SO4 into polymer matrix, inducing phase separation of PEDOT:PSS, thus increasing PEDOT crystallinity and partially removing of PSS component. As a result, the as‐prepared pristine PEDOT:PSS aerogels exhibit a high electrical conductivity of 1200 ± 231 S m−1 along the freezing direction at a low density of 15.3 ± 1.5 mg cm−3, enhanced mechanical properties, and a competitive electromagnetic interference shielding efficiency of 25 115 dB cm2 g−1. Moreover, the compressed aerogels show good performances as active materials in symmetrical supercapacitors with thickness‐independent capacitance (maximum 2.1 F cm−2 at 1.0 mA cm−2) and in current collector‐free micro‐supercapacitors processed by laser carving. [ABSTRACT FROM AUTHOR]

In this work, a simple and cost-effective method was proposed and developed to prepare a novel multilayer-structured Kevlar®@nickel-phosphorus-boron@copper@copper stearate (Kevlar®@Ni–P–B@Cu@CS) composite fabric with high conductivity, high flexibility, high hydrophobicity, and high durability to effectively shield electromagnetic interference (EMI). In this method, an amorphous Ni–P–B alloy nanolayer was initially deposited onto a Kevlar® fabric via electroless plating. Afterward, a crystalline Cu nanolayer was deposited as the second layer via electroplating. Finally, a monolayer of copper stearate was innovatively self-assembled as the outermost protective layer. The Cu deposition was effectively adjusted and designed by controlling the plating current and plating time. The electrical resistance and contact angle of the optimized Kevlar®@Ni–P–B@Cu@CS composite fabric were as low as 3.2 mΩ sq−1 and as high as 115.39°, respectively, indicating that the fabric could withstand bending, tape-off, corrosion, and accelerated environmental tests. The average EMI-shielding efficiency of the durable composite fabric was 93.9 dB in the frequency range of 8.2–12.4 GHz, which was mainly attributed to the absorption loss. Thus, the proposed material configuration has promise for applications in aviation, aerospace, telecommunication, wearable devices, and military industries. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive numerical investigation of the electromagnetic interference (EMI) shielding capabilities of a conductive polymer nanocomposite incorporated with carbon nanotubes (CPNC) in the X-band. The investigation is conducted using a commercial finite element simulation package, Ansys HFSS. The study focuses on analyzing the EMI shielding effectiveness (SE) of CPNC by varying the weight percent (wt%) of carbon nanotubes (CNTs), thickness, and shape of the shielding material. Our outcomes show that the EMI SE of CPNC increases with the wt% of CNTs. Notably, a maximum EMI SE is observed around 90 dB due to absorption (SEA) at a 4 mm pallet-shaped CPNC and -180 dB for a hollow cylindrical CPNC (22.86 mm outer diameter and 3 mm thickness) with 2 wt% of CNT. The EMI SE due to absorption (SEA) at a pallet thickness of 4 mm exhibits a significant improvement of 107% compared to the SEA observed at a thickness of 1 mm. These findings highlight the exceptional absorption capabilities and lightweight nature of CPNC, rendering it a promising shielding material for aerospace and satellite communication applications. Highlights • EMI SE of CPNC increases with the wt% of CNT in the polypyrrole (PPy) matrix. • The percolation threshold is observed at a low 2 wt% concentration of CNT. • Thickness of the shielding material influences the EMI SE of CPNC. • CPNC provides absorption-dominated shielding. [ABSTRACT FROM AUTHOR]

Conductive aerogel is a material with excellent electrical conductivity and unique three-dimensional nano-network structure, formed by doping conductive fillers into the aerogel, or directly through conductive substances such as conductive polymer. In addition, it has the advantages of high porosity, high specific surface area, low density, excellent flexibility and low cost. The purpose of this review is to summarize the research status of conductive aerogels to open up new ideas for scientific research in related fields for readers. Firstly, we summarize the assembly strategies of conductive aerogel. The assembly process includes preparation and drying of the gel. In addition, the aging process is involved. Secondly, we review its conduction mechanism. Then, the effects of pressure, temperature and humidity on the properties of conductive aerogels are summarized. Notably, conductive aerogel has piezoresistive effect because of its elasticity and compressibility. Finally, based on the properties of conductive aerogels and their advantages in electrical conductivity, we summarize the applications of conductive aerogels in supercapacitor, electrocatalysis, sensors and electromagnetic interference shielding. This review summarizes the current development and application of conductive aerogel in recent years, which provides strong support for the future development of conductive aerogel. [ABSTRACT FROM AUTHOR]

MXenes are a promising class of two‐dimensional transition metal carbides, nitrides, and carbonitrides, widely utilized in diverse fields such as energy storage, electromagnetic shielding, electrocatalysis, and sensing applications. Their potential in chemical sensing is particularly noteworthy, where optimizing surface chemistry for strong interaction with target analytes and increasing surface area for efficient gas adsorption are crucial factors. In this study, a versatile and general self‐assembly method for fabricating nanometer‐scale thin films of surface‐functionalized MXene, enabling high‐performance gas sensors is developed. By dropping MXene dispersed in organic solvents onto nonsolvents, rapid formation of nanometer‐scale films is achieved. This method allows easy adjustment of film properties by using different solvent‐nonsolvent combinations, leading to improved optoelectronic properties compared to conventional techniques. The surface‐functionalized MXenes using ADOPA ligands greatly enhance the gas response and long‐term environmental stability compared to pristine MXenes. Computational methods are also employed to gain insights into the molecular interactions and changes in electronic structure that contribute to the enhanced sensing properties. Furthermore, the environmental stability of MXene sensors is largely enhanced after surface functionalization, which can be attributed to increased surface hydrophobicity. Overall, this innovative technique opens up opportunities for tailoring MXene thin films for specific applications. [ABSTRACT FROM AUTHOR]

Herein, a new lightweight syntactic foam is reported with strong mechanical properties, unique multifunctionalities, and recyclability. Multifunctionality of materials and structures has gained ever‐increasing interest as an excellent approach to designing minimalistic systems. Inspired by nature, these materials can perform multiple functions besides bearing a load. Due to their shape‐changing and damage‐healing property, shape memory vitrimers (SMVs) are a great example of multifunctional materials readily exploited for many applications. Using nickel and silver‐plated hollow glass microbubbles (HGMs), an SMV‐based syntactic foam is introduced here that supplements the multifunctionality of SMVs with electrical conductivity and ferromagnetism, which enables a series of additional potentials such as strain sensing, damage monitoring, Joule heating, and electromagnetic interference shielding. Despite its low density and outstanding mechanical properties, this foam exhibits shape memory behavior, which can be triggered by an electrical current, and damage healing capability due to its reversible dynamic covalent bonds. Especially its recyclability makes recycling the expensive silver‐coated and nickel‐coated HGMs feasible, making this foam cost‐effective and environmentally sustainable. With its many features and economical manufacturability, this syntactic foam has a potential to be utilized in many applications, ranging from aerospace structures to biomedical devices to household items. [ABSTRACT FROM AUTHOR]

Highlights: We present a method that utilizes ionic liquid-enhanced nanomaterial assembly to fabricate highly stable and large-area MXene-silver nanowire electrodes with ordered layered structures. This approach emphasizes the use of hydrophobic and nonvolatile ionic liquids, which form stable interfaces with water by reducing interface energy, preventing the sedimentation loss of nanomaterials during assembly. The prepared electrodes not only exhibit excellent optoelectronic properties (9.4 Ω sq−1 sheet resistance and 93% transmittance), but also have exceptional antioxidant capacity. The controlled assembly of nanomaterials has demonstrated significant potential in advancing technological devices. However, achieving highly efficient and low-loss assembly technique for nanomaterials, enabling the creation of hierarchical structures with distinctive functionalities, remains a formidable challenge. Here, we present a method for nanomaterial assembly enhanced by ionic liquids, which enables the fabrication of highly stable, flexible, and transparent electrodes featuring an organized layered structure. The utilization of hydrophobic and nonvolatile ionic liquids facilitates the production of stable interfaces with water, effectively preventing the sedimentation of 1D/2D nanomaterials assembled at the interface. Furthermore, the interfacially assembled nanomaterial monolayer exhibits an alternate self-climbing behavior, enabling layer-by-layer transfer and the formation of a well-ordered MXene-wrapped silver nanowire network film. The resulting composite film not only demonstrates exceptional photoelectric performance with a sheet resistance of 9.4 Ω sq−1 and 93% transmittance, but also showcases remarkable environmental stability and mechanical flexibility. Particularly noteworthy is its application in transparent electromagnetic interference shielding materials and triboelectric nanogenerator devices. This research introduces an innovative approach to manufacture and tailor functional devices based on ordered nanomaterials. [ABSTRACT FROM AUTHOR]

Bamboo is one of the green building materials that have been used for centuries. Combining with metal materials will endow bamboo with new functions, such as weather resistance, anti-corrosion, conductivity, and electromagnetic shielding. However, there is a natural barrier between bamboo and metal materials. This paper proposes fabrication of novel bamboo-based metal composites (BMC) which are composed of bamboo substrate and metal coating, without any adhesive, using an efficient and sustainable arc thermal spraying technique. In this method, the metal wire is melted and deposited on the bamboo substrate through a high-temperature heat source. In the feasibility experiment, arc spraying using aluminum as the wire electrode was selected. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) were used to observe and test the fabricated specimens. It was demonstrated that when the spraying voltage was 40 V, the deposition rate was as high as 5.8 g/min with the average thickness of the metal coating exceeding 400 μm. The surface of the BMC aluminum coating was flat, continuous, and compact with an average roughness of about Ra 3.0 μm. Based on experimental results, the integrity of bamboo substrate in thermal spraying was discussed. Results from SEM–EDS test showed that there are crack areas and adhesion areas between bamboo and metal coatings, and the highest bonding strength exhibited over 1.0 MPa. This work provides a new practice of fabricating novel BMC through a green manufacturing method with high efficiency. The findings of this study may be useful in understanding the preparation of BMC and can help find their suitability for a wide range of applications. [ABSTRACT FROM AUTHOR]

A variety of fascinating applications, including 5G communication devices, high-speed data transfer, and large-scale Internet of Things (IoT), make life easier with 5G technology. Despite the 5G's superior features, the percentage of electromagnetic (EM) waves in the environment execute a significant increase, unpleasantly. Broadband metamaterial absorbers are an appealing alternative to gather these unwanted signals. This study aims to numerically investigate a broadband metamaterial absorber (MMA) in the 5G high-frequency spectral range with the metasurface formed with coupled resistors. In addition, the 24.25-27.5GHz frequency range, one of the high-frequency 5G bands used by selected countries such as the European Union and China, was preferred. The minor aim of this study is that the usage of coupled elements as resistors may have the ability to increase the absorption bandwidth and magnitude. Comprehensive simulations were performed using the finite integration technique (FIT) utilized by the CST Microwave Studio program to investigate the absorber performance and other relevant parameters. The unit cell design is created metal-substrate-metal structures as asymmetric, single-layer, and easy to implement. The absorption responses are investigated according to the oblique incidence angle, polarization angle for TE &TM modes. The suggested MMA provided an absorbency response above 87.6% in the frequency range 24.20-27.30GHz under normal incidence. Moreover, to comprehend the physical mechanism on absorption, the top and bottom surfaces of the absorber's electric field and surface current distributions are assessed. The designed MMA resulting in relatively high performance and polarization insensitive is helpful for electromagnetic interference (EMI) shielding of 5G signals in the FR2/mmWave frequency regime. [ABSTRACT FROM AUTHOR]

Graphene and its derivatives have been confirmed to be among the best fillers for rubber due to their excellent properties, such as high mechanical strength, improved interface interaction, and strain-induced crystallization capabilities. Graphene rubber materials can be widely used in tires, shoes, high-barrier conductive seals, electromagnetic shielding seals, shock absorbers, etc. In order to reduce the graphene loading and endow more desirable functions to rubber materials, graphene-based hybrid fillers are extensively employed, which can effectively enhance the performance of rubber composites. This review briefly summarizes the recent research on rubber composites with graphene-based hybrid fillers consisting of carbon black, silica, carbon nanotubes, metal oxide, and one-dimensional nanowires. The preparation methods, performance improvements, and applications of different graphene-based hybrid fillers/rubber composites have been investigated. This study also focuses on methods that can ensure the effectiveness of graphene hybrid fillers in reinforcing rubber composites. Furthermore, the enhanced mechanism of graphene- and graphene derivative-based hybrid fillers in rubber composites is investigated to provide a foundation for future studies. [ABSTRACT FROM AUTHOR]

The application of absorbing materials for electromagnetic shielding is becoming extensive, and the use of absorbents is one of the most important points of preparing absorbing foam materials. In this work, epoxy resin was used as the matrix and carbonyl iron powder (CIP) was used as the absorbent, and the structural absorbing foam materials were prepared by the ball mill dispersion method. Scanning electron microscopy showed that the CIP was evenly dispersed in the resin matrix. The foam structures formed at pre-polymerization times of 10 min, 30 min and 50 min were analyzed, and it was found that the cell diameter decreased from 0.47 mm to 0.31 mm with the increase in the pre-polymerization time. The reflectivity of the frontal and reverse sides of the foam gradually tends to be unified at frequencies of 2–18 GHz. When the CIP content increased from 30 wt% to 70 wt%, the cell diameter increased from 0.32 mm to 0.4 mm, and the uniformity of CIP distribution deteriorated. However, with the increase in the CIP content, the absorption properties of the composite materials were enhanced, and the absorption frequency band broadened. When the CIP content reached 70 wt%, the compression strength and modulus of the foam increased to 1.32 MPa and 139.0 MPa, respectively, indicating a strong ability to resist deformation. [ABSTRACT FROM AUTHOR]

Three types of composites were tested for electromagnetic interference (EMI) absorption shielding effectiveness, the curing process, and their physical–mechanical properties. For the first type of composites, nickel–zinc ferrite, manganese–zinc ferrite, and both fillers in their mutual combinations were incorporated into acrylonitrile–butadiene rubber. The overall content of the filler, or fillers, was kept at 200 phr. Then, carbon black or carbon fibers were incorporated into each rubber formulation at a constant loading of—25 phr, while the content of magnetic fillers was unchanged, at —200 phr. This work focused on the understanding of correlations between the electromagnetic shielding parameters and electrical conductivity of composites in relation to their EMI absorption shielding effectiveness. The absorption shielding abilities of materials were evaluated within a frequency bandwidth from 1 MHz to 6 GHz. This study revealed good correlation among permittivity, conductivity, and EMI absorption effectiveness. Although the absorption shielding efficiency of composites filled only with ferrites seems to be the highest, the absorption maxima of those composites reached over 6 GHz. The application of carbon-based fillers resulted in the higher electrical conductivity and higher permittivity of composites, which was reflected in their lower absorption shielding performance. However, the composites filled with ferrites and carbon-based fillers absorbed electromagnetic radiation within the desired frequency range. The presence of carbon-based fillers caused improvement in the tensile behavior of composites. This study also demonstrated that the higher the ratio of nickel–zinc ferrite in combined magnetic fillers, the better the absorption shielding efficiency. [ABSTRACT FROM AUTHOR]

Metal coatings with micron thickness, high conductivity, and a unique structure that can provide exceptional electromagnetic interference (EMI) shielding performance to insulation substrates are highly desirable, especially if the production method is inexpensive, pollution‐free, and efficient. In this study, the Ar/H2 mixed atmospheric pressure plasma jet (APPJ) was utilized to reduce AgNO3 to produce PC + ABS substrates coated with silver nanoparticles (AgNPs). It was found that the low roughness AgNPs coating has a multilayer network structure, which could exhibit high conductivity and excellent EMI shielding effectiveness (SE). In conclusion, this method is an excellent choice for producing metal EMI shielding coating. [ABSTRACT FROM AUTHOR]

The main objective of this paper is to design a Frequency Selective Surface (FSS) generating multi stop-band and having the property of a large scanning angle from a mixed polarization insensitivity structure for GPS, PCS, WiFi, IEEE S-band radar, 5G mobile phones, (802.11j) WLAN applications. To fulfill the objective, a hexa band-stop FSS has been developed using a novel symmetrical structure with a compact dimension of 0.095 λ 0 × 0.095 λ 0 , where λ 0 is the wavelength of free space at 1st resonant frequency. The proposed FSS covers a broad scanning angle of 60 0 for shielding electromagnetic wave radiation and smaller resonant frequency ratio ( f n + 1 / f n ) to improve compactness under TE and TM polarizations. The six achieved stop frequency bands are 1.36 GHz–1.56 GHz, 1.66 GHz–1.99 GHz, 2.34 GHz–2.46 GHz, 3.08 GHz–3.42 GHz, 3.6 GHz–4.12 GHz and 4.5 GHz–5 GHz for improving shielding performance. [ABSTRACT FROM AUTHOR]