Composites For Electromagnetic Interference Shielding Research Articles

Nacre-like Anisotropic Multifunctional Aramid Nanofiber Composites for Electromagnetic Interference Shielding, Thermal Management, and Strain Sensing.

Developing multifunctional flexible composites with high-performance electromagnetic interference (EMI) shielding, thermal management, and sensing capacity is urgently required but challenging for next-generation smart electronic devices. Herein, novel nacre-like aramid nanofibers (ANFs)-based composite films with an anisotropic layered microstructure were prepared via vacuum-assisted filtration and hot-pressing. The formed 3D conductive skeleton enabled fast electron and phonon transport pathways in the composite films. As a result, the composite films showed a high electrical conductivity of 71.53 S/cm and an outstanding thermal conductivity of 6.4 W/m·K when the mass ratio of ANFs to MXene/AgNWs was 10:8. The excellent electrical properties and multi-layered structure endowed the composite films with superior EMI shielding performance and remarkable Joule heating performance, with a surface temperature of 78.3 °C at a voltage of 2.5 V. Additionally, it was found that the composite films also exhibited excellent mechanical properties and outstanding flame resistance. Moreover, the composite films could be further designed as strain sensors, which show great promise in monitoring real-time signals for human motion. These satisfactory results may open up a new opportunity for EMI shielding, thermal management, and sensing applications in wearable electronic devices.

Biobased, recyclable, and multi-functional high-performance composites for electromagnetic interference shielding

High-performance fiber-reinforced thermoset composites (FRTCs) are highly demanded in modern society but are challenged because they depend on nonrenewable fossil-based feedstocks, are hard to recycle after service, and lack advanced functions. Here, we report a methodology to fabricate sustainable, recyclable, high-performance, and multifunctional FRTCs from renewable feedstocks such as vanillin, glycerol triglycidyl ether, 1,10-diaminodecane, and basalt fiber. We designed a mussel-inspired approach to prepare high conductive basalt fiber (CBF), and combined the CBF with a fully biobased covalent adaptable network (CAN) based on dynamic imine bonds to produce the composites i.e., CAN/CBF laminar composites through a solvent-free method. The CAN/CBF composites showed highly reinforced mechanical properties and multiple functionalities including electromagnetic interference shielding, shape memory, and self-adhesion characters through combination in the advantages and functions of both CAN and CBF. Furthermore, we demonstrated that the CAN matrix and the reinforced CBF can be recycled separately and can be further reformed to the CAN/CBF composites due to the dynamic nature of the CAN matrix. Our study thus provides an urgently applicable approach for advanced manufacturing toward the green and circular advanced composites economy.

Tellurium Nanoparticles Incorporated into Electrospun Poly(acrylonitrile) Nanofibers, Followed by Carbonization and Their Poly(dimethylsiloxane) Composites for Electromagnetic Interference Shielding

Tellurium Nanoparticles Incorporated into Electrospun Poly(acrylonitrile) Nanofibers, Followed by Carbonization and Their Poly(dimethylsiloxane) Composites for Electromagnetic Interference Shielding

Fabrication of anisotropic carbon aerogels from cellulose nanofiber/graphene oxide composites for electromagnetic interference shielding

Aerogels have been considered as a promising electromagnetic interference (EMI) shielding materials due to their lightweight, compressibility, high elasticity and electrical conductivity. In order to improve their EMI shielding effectiveness (EMI SE), developing carbon aerogel with adjustable microstructure is still an urgent problem. Herein, carbon aerogels were fabricated from bamboo cellulose nanofiber (CNF)/graphene oxide (GO) composites with the layered interconnected structure via bidirectional freezing and carbonization. The prepared aerogels exhibited high mechanical strength in the parallel lamellar direction and excellent compression flexibility in the vertical lamellar direction. After 300 cycles of compression in the vertical lamellar direction, 97% of its original height can be recovered. The absolute shielding effectiveness of anisotropic carbon aerogels could achieve 23,628 dB cm2 g−1 with an ultralow density (3 mg cm−3). This study explores the correlation between the structure of carbon aerogels and their EMI shielding properties, offering an eco-friendly approach to produce lightweight anisotropic carbon aerogels for EMI shielding.

Aligned, carbon nanofibers containing barium titanate and their polydimethylsiloxane composites for electromagnetic interference shielding

The rapid development of wireless communication technology and miniaturization of electronic devices have escalated the demand for high-performance electromagnetic interference (EMI) shielding materials which are light weight, waterproof, and flexible. Herein, we have demonstrated fabrication of aligned and non-aligned one-dimensional (1-D) N-doped carbon nanofibers (CNF) incorporated with barium titanate (BaTiO3) nanoparticles (NPs) [BaTiO3–CNF] for EMI shielding in X, Ku, and K-band. BaTiO3–CNF was prepared through electrospinning followed by carbonization at 900 °C. The aligned BaTiO3–CNF exhibited better EMI shielding effectiveness (81 dB with a thickness of 0.24 mm) compared to the non-aligned BaTiO3–CNF (59.2 dB). Alignment of N-doped CNF enhanced electronic conduction in axial direction of the fibers and exhibited higher electrical conductivity of 1.4 S cm−1. The alignment also improved multiple internal reflections and interfacial polarization in the layered structure of the CNF. PDMS composites of BaTiO3–CNF were prepared by hand-layup method to make them flexible, and the composites exhibited similar EMI shielding properties as that of BaTiO3–CNF. Alignment of suitably doped CNF may open up new opportunities for industrial-scale production of shielding materials that are waterproof, lightweight, and flexible.

Interfacial engineering of hybrid MXene-Ni-CF tri-core–shell composites for electromagnetic interference shielding and E-heating applications

In response to the the needs for multifunctional carbon fiber reinforced polymer (CFRP) composites, we present a novel, tri-core–shell CFRP consisting of MXene, nickel (Ni), and CF synthesized throughlayer-by-layer assembly. The hybridcomposites demonstrate remarkable electrical conductivity and electromagnetic interference (EMI) shielding, alongside efficient electrical (E-) heating properties. Additionally, the MXene-Ni-CF/EP hybrid composite displayed improved flexural strength and ILSS compared to Ni-CF/EP composite. Outstanding enhancements were observed in both the through-thickness and in-plane electrical conductivities, with a 116-fold and 14-fold improvement, respectively, attributed to the complex MXene-Ni-CF conductive paths. The hierarchical compositessignificantly outperformed the state of the art and demonstrated a superior EMI shielding efficiency of 72.4 dB by virtue of the dielectric and magnetic loss mechanisms. Thelow-voltage-driven E-heating capacity could be utilized for de-icing applications due to the thermally conductive networks. The producedcomposites offer a highly promising solution to tackle challenges associated with lightning strikes and icy weather conditions, while also aligning with the goal of cost-effective industrial production.

Synthesis of M-type hexaferrite reinforced graphene oxide composites for electromagnetic interference shielding

This study focused on addressing the increasing demand for materials that can effectively shield against electromagnetic interference. In particular, Ba0.7Mn0.3Nd0.1Fe11.9O19 M-type hexaferrite was synthesized using the sol–gel auto-combustion method and sintered at 1050 °C. The modified Hummer process was used to prepare graphene oxide (GO), and three composites were then synthesized with the ultrasonication method, which were denoted as C-1 (90 % M-ferrite + 10 % GO), C-2 (80 % M-ferrite + 20 % GO), and C-3 (70 % M-ferrite + 30 % GO). X-ray diffraction (XRD) analysis confirmed the formation of the hexagonal phase of the M-type barium hexaferrite and GO. A prominent peak at an angle of 8.82° corresponding to the (001) reflection was observed by XRD analysis for the GO sample and it confirmed the effective oxidation of graphite and formation of GO. Scanning electron micrographs of M-type hexaferrite demonstrated the formation of platelet-like grains with hexagonal shapes, which were suitable for microwave absorption. The direct current electrical resistivity at room temperature was determined as 2.08 × 10−8 Ω-cm for the M-type ferrite, and the resistivity of the composites decreased as the concentration of GO increased due to the superior conductivity of GO compared with the ferrite. The dielectric properties of all samples followed the Maxwell–Wagner model. The dielectric characteristics increased in magnitude as the GO content increased. The AC magnetic susceptibility decreased for the M-type ferrite and three composites as the temperature increased to eventually reach a steady state at a specific temperature known as the Curie temperature. Except for GO, the Curie temperatures of all samples were within the range of 348 K–450 K. Coupling magnetic ferrite with GO allows the magneto-electrical characteristics to be tuned, with possible uses in electronic devices, electromagnetic shielding, supercapacitors, and water purification.

Construction of sandwich-structured Cu-Ni wood-based composites for electromagnetic interference shielding

Constructing a controllable electromagnetic gradient toward advanced electromagnetic interference shielding composites has become a development trend. A sandwich-structured Cu-Ni wood composite (CNWC) was successfully fabricated via a simple electroless Cu-Ni procedure. The obtained results showed that the Cu-Ni wood composite material exhibited excellent electromagnetic shielding effectiveness (EMSE) (average value 57.4 dB) in the entire X-band (from 8.2 to 12.4 GHz) in case of low thickness (0.4 mm) and low density (0.87 g/cm3). Herein, the wood-based composites possessed maximum saturation magnetization which was up to 7.7 emu/g and the conductivity increased to 1930 S/cm. The dielectric loss and magnetic loss are important ways of electromagnetic wave attenuation in Cu-Ni-based electromagnetic shielding materials, and are the key to the absorption of most electromagnetic waves by composites. The electromagnetic gradient sandwich-structure can realize multi-dielectric interface loss and multiple reflection loss. When the electromagnetic wave enters the porous structure inside the wood, the electromagnetic wave generates internal scattering and multiple reflections in the hole. The synergistic effect of dielectric loss and magnetic loss to improve the loss ability of electromagnetic wave.

Recent advances and perspectives on silver-based polymer composites for electromagnetic interference shielding

Silver/polymer composites have attracted significant interest in the field of electromagnetic interference shielding. This review prospects the current progress, the state-of-the-art, and the future development of silver/polymer composites.

The role of magnetic nano CoFe2O4 and conductive MWCNT/graphene in LDPE-based composites for electromagnetic interference shielding in X-band

The use of polymer composites containing ferrite based magnetic fillers and conducting fillers are highly appreciated as materials for microwave shielding. In this regard, herein we present systematic optimization of compositional parameters by varying CoFe 2 O 4 and MWCNT/Graphene nanoplatelets to achieve efficient electromagnetic shielding in Low density polyethylene polymer. The magnetic filler, CoFe 2 O 4 was prepared by facile solution combustion process and the chemically exfoliated Graphene and CVD-derived MWCNT are used as conducting filler. Various compositions containing different weight ratios of CoFe 2 O 4 and Graphene nanoplatelets on the EMI shielding efficiency of LDPE composite is studied using vector network analyzer in the frequency range of 8–12 GHz. The critical concentration of all the materials in bringing synergy was evaluated. The combination of LDPE:MWCNT:GNP:CoFe 2 O 4 : 50:5:40:5 was found to be optimum concentration to bring a synergetic effect for gaining excellent dielectric, ohmic and magnetic losses in the X-band. Maximum total shielding effectiveness of about 49 dB was achieved at 10.3 GHz within the frequency range studied. • The use of magnetic CoFe 2 O 4 and carbon based MWCNT/ Graphene as fillers in LDPE matrix for enhanced shielding behavior. • Systematic optimization of the ferrite, carbon nanotubes and graphene is carried out to achieve maximum shielding effectiveness. • The synergetic effect is proved at an optimum fillers concentration and are correlated to the impedance and conductivity variations of the composites.

Designing Sandwich Architecture Towards Glass Fiber/Epoxy Reinforced Multi-walled Carbon Nanotube Buckypaper Composites for Electromagnetic Interference Shielding

Designing Sandwich Architecture Towards Glass Fiber/Epoxy Reinforced Multi-walled Carbon Nanotube Buckypaper Composites for Electromagnetic Interference Shielding

Flexible carbon fiber-based composites for electromagnetic interference shielding

Flexible carbon fiber-based composites for electromagnetic interference shielding

Vertically Aligned Carbon Nanotube@Graphene Paper/Polydimethylsilane Composites for Electromagnetic Interference Shielding and Flexible Joule Heating

High-performance electromagnetic interference (EMI) shielding and thermal management materials with ultraflexibility, high strength, outstanding stability under mechanical deformation, and low cost are urgently demanded for modern integrated electronic and telecommunication systems. However, the creation and application of such desirable materials is still a potent challenge. Herein, we develop such a high-performance multifunctional multilayer composite, known as vertically aligned carbon nanotube@graphene paper/polydimethylsilane (VACNT@GP/PDMS), which involves the in situ growth of VACNTs onto GPs, vertical stacking of VACNT@GP layers, and infiltration of PDMS. The EMI shielding and mechanical properties of multilayer composites can be dramatically increased by increasing the number of VACNT@GP layers. Benefiting from the conduction loss in highly conductive GPs and polarization of huge VACNT–PDMS–VACNT microcapacitor networks, the multilayer composite with four VACNT@GP layers exhibits a superior EMI SE of 106.7 dB over a broad bandwidth of 32 GHz, covering the entire X-, Ku-, K-, and Ka-bands, which far suppresses the values of most of the reported EMI shielding materials. Moreover, the multilayer composites show excellent thermal management performance such as a high Joule-heating temperature at low supplied voltages, rapid response time, and sufficient heating stability. In addition, remarkable flexibility, high tensile strength (up to 13.4 MPa), and super stability under mechanical deformation (nearly no EMI SE degradation after repeatedly bending 10,000 times) are also discovered. These excellent comprehensive properties, along with the ease of low-cost mass production, pave the way for the practical applications of multilayer VACNT@GP/PDMS composites in EMI shielding and thermal management.

Electromagnetic interference cognizance and potential of advanced polymer composites toward electromagnetic interference shielding: A review

AbstractThe exigency of electromagnetic shielding is derived from the electromagnetic pollution caused by the widespread use of electronic devices. Electromagnetic waves from innumerable electrical sources radiate in the atmosphere and generate electromagnetic interference (EMI). Such EMI can interrupt other instruments and threaten human health. Therefore, future designs of electronic devices, regardless of their size and use, necessitate advanced electromagnetic shielding materials and techniques that can limit or completely block the transmission of electromagnetic waves in the atmosphere. The purpose of this review is to investigate the use of polymer‐based composites for EMI shielding and study their configurations. The objectives of this study and the societal and environmental impacts of electromagnetic waves are discussed in detail. The available reports, the worldwide contribution by researchers in the field, the limitations of the available materials, and the inventions required have directed our interest toward this area of research. The review summarizes EMI shielding cognizance, current research gaps, and future recommendations.

ZIF-67/wood derived self-supported carbon composites for electromagnetic interference shielding and sound and heat insulation

Co/C@WC composites showed better electromagnetic shielding performance and also exhibited sound insulation, temperature resistance and good mechanical performance.

Carbon foams derived from emulsion-templated porous polymeric composites for electromagnetic interference shielding

A series of carbon foams (CFs) were fabricated from the emulsion-templated porous polymeric composites, following with hypercrosslinking and carbonization. The polymeric composites were constituted by syndiotactic polystyrene (sPS), carbon nanotubes (CNTs) and magnetic Ni@CNTs. The addition of nanofillers was beneficial to the carbonization, resulting in less shrinkage, higher graphitization degree, lager emulsion-templated voids and nanofibrous pore walls. The composite CFs showed higher robustness (up to 19.7 MPa cm3 g−1), more hydrophobic surface (water contact angle up to 148°) and larger specific surface area (up to 144 m2 g−1). In particular, the electrical conductivity (up to 97 S m−1) and electromagnetic interference (EMI) shielding effectiveness (EI) (up to 78.0 dB) were greatly enhanced when the CNTs and Ni@CNTs were simultaneously employed. The conduction losses caused by conductive network of residual carbon network of carbonized sPS and the nanofillers, polarization losses from interfacial polarization between carbonized sPS and nanofillers, dielectric loss within mesopores and magnetic loss from Ni@CNTs contributed to the enhanced shielding effectiveness. The carbon foams can be prefect succedanea of the commercial EMI shielding materials in the aerospace and wireless telecommunication fields.

Graphene Infused Ecological Polymer Composites for Electromagnetic Interference Shielding and Heat Management Applications.

In the age of mobile electronics and increased aerospace interest, multifunctional materials such as the polymer composites reported here are interesting alternatives to conventional materials, offering reduced cost and size of an electrical device packaging. We report a detailed study of an ecological and dual-functional polymer composite for electromagnetic interference (EMI) shielding and heat management applications. We studied a series of polylactic acid/graphene nanoplatelet composites with six graphene nanoplatelet loadings, up to 15 wt%, and three different flake lateral sizes (0.2, 5 and 25 μm). The multifunctionality of the composites is realized via high EMI shielding efficiency exceeding 40 dB per 1 mm thick sample and thermal conductivity of 1.72 W/mK at 15 wt% nanofiller loading. The EMI shielding efficiency measurements were conducted in the microwave range between 0.2 to 12 GHz, consisting of the highly relevant X-band (8–12 GHz). Additionally, we investigate the influence of the nanofiller lateral size on the studied physical properties to optimize the studied functionalities per given nanofiller loading.

Advances in waterborne polymer/carbon material composites for electromagnetic interference shielding

Electromagnetic interference (EMI) shielding materials are of great importance for modern daily life, military actions and precise instrument protection because of the complex electromagnetic pollution caused by explosive growth of telecommunications and electronics devices. The conductive polymer composites (CPCs) have been proved to be one of the most promising EMI shielding materials both in fundamental research and practical application due to it set of intriguing lightweight, good processability, low density, chemical stability and excellent mechanical properties. Carbon materials (e.g. graphene, carbon nanotubes, carbon fiber, carbon black) based composites have occupied a prominent position in CPCs for EMI shielding. Not only the electromagnetic pollution should be eliminated or solved, but also the pollution coming from the preparation or processing of polymers. In this regard, waterborne polymer/carbon material composites for EMI shielding can meet the demand. Waterborne polymer will affect the EMI SE performance remarkably by improving the interfacial interaction between carbon materials and polymer and further structure designing of the composite. The composite structure forms including homogeneous structures, multilayer structures, segregated structures and porous structures are mainly discussed in details in this review which may inspire the design for more environment-friendly EMI shielding materials.

Lightweight and high-strength GMT/PEFP/GNP composites with absorb-dominated electromagnetic interference shielding property

As the problem of electromagnetic wave pollution is becoming more and more serious in our daily life, it is urgent to develop a kind of electromagnetic interference (EMI) shielding materials with high-strength and high absorptivity to meet the demand of industrial application. In this study, a facile method is developed to prepare EMI shielding composites with both powerful absorbing and robust mechanical properties by impregnating the suspensions of graphite nanoplatelets (GNP) and polyacrylate expandable foam particles (PEFP) into the porous glass fiber mat reinforced thermoplastics (GMT), and then hot forming and pressing, the thickness of GMT/PEFP/GNP composites is 2 mm. GNP not only acted as an efficient conductive pathway in the GMT/PEFP/GNP composites matrix, but also formed a conductive cell structure with the foamed PEFP, which increased the electromagnetic waves absorption. The total shielding efficiency (SET) of the GMT/PEFP/GNP-4.0 wt% composite is up to 33.8 dB at 11 GHz, and the power coefficient of reflectivity is 0.71, which is lower 17% than that of GMT/GNP composites without the cell structure constructed by PEFP in the matrix. Furthermore, the melting of polypropylene (PP) in the mats act as the interface adhesive for glass fiber (GF) and GNP, so the tensile strength is enhanced up to 22.8 MPa for the GMT/PEFP/GNP-4.0 wt% composites with lightweight, due to the formation of cell structure constructed by the PEFP. Therefore, this paper provides a simple method to prepare lightweight and high-strength GMT/PEFP/GNP composites for EMI shielding, which is of great significance for industrial application.

Nanoelectromagnetic of a highly conductive 2D transition metal carbide (MXene)/Graphene nanoplatelets composite in the EHF M-band frequency

Highly conductive materials, with minimal thickness and capable to afford electromagnetic interference (EMI) shielding, are highly advantageous, particularly if they are able to be easily processed into thin films. Here, we demonstrate the potential of a sandwich-like structure of a two-dimensional Ti3C2Tx MXene/Graphene nanoplatelets (GNPs) composites for EMI shielding in the extreme high frequency (EHF) M-band, ranging from 60 to 80 GHz. First, we investigated systematically the microstructural and electrical transport properties of these composites with respect to the GNP contents. After graphene integration, the composite-surface roughness has been found to decrease, while both electrical conductivity and Hall carrier mobility demonstrated a clear trend to increase, reaching the values of ∼105 S/cm and 55 cm2/V, respectively, for only 2.5 wt % of graphene content, reporting thereby one of the most electrically conductive MXene based composite to date. Furthermore, a 1.75 μm-thick Ti3C2Tx MXene/GNP film was found to exhibit an EM absorbance of about 64 dB, which is one of the highest values, normalized to the thickness, among tested materials so far. This remarkable performance could be associated to three key factors, namely the superior transport properties of the composite films, the dominant absorption mechanism, and the multiple internal reflections from Ti3C2Tx and graphene multilayers configuration. These reported results would lead to unprecedented applications in the fields of space, aeronautics, radars, air travels and mobile phones.