Excellent Electromagnetic Interference Research Articles

Multifunctional-structural integrated wood cellulose‑based composite with Magpie’s Nest-shaped enhance flame retardancy and electromagnetic interference shielding

The construction of multifunctional hydrophobic wood with electromagnetic interference shielding effectiveness had attracted great interest, at the same time, the problem of wood flammability must also be solved. In this study, the effectiveness of DOPO-based P and Zn complexes in improving wood flame retardancy and electromagnetic interference shielding effectiveness, and the outstanding contribution of lignocellulose skeleton and multi-interface to shielding effectiveness was demonstrated. DOPO-based P and Zn complexes with “Needle-punched” structure and much functional groups were loaded on the wood surface, and then micro-nano metal Ni particles were deposited. Through the optimization of the wood surface and itself structure, and the construction of a complete conductive network. Wood/ZnP/Ni composites electromagnetic interference shielding effectiveness couold reach 65.04 dB in the X-band. It was worth noting that the lignocellulose skeleton prepared by the top-down method and multi-interface structure increase electromagnetic interference shielding effectiveness by 10.71 % and 33.89 %, respectively. In addition, the synergistic effect of DOPO-based P and Zn complexes and the introduction of PDMS layer improved the flame retardancy (limiting oxygen index was 35.3 %) and hydrophobicity (contact angle was 133.07°), which avoided the wood poor durability problem in use. There was no doubt that it provided a new strategy for the preparation of novel materials with low-cost and extremely excellent electromagnetic interference shielding properties.

Multifunctional composite paper fabricated by graphene oxide/tannin decorated carbon fiber with excellent electromagnetic interference shielding, antibacterial and sound absorption properties

Considering the distinctive oxidative coupling characteristic of tannin acid, it was used as an interfacial interlayer to build a nano-coating structure on the surface of carbon fiber (CF)using amino-modified graphene oxide (GON) via Schiff base reaction. Furthermore, a kind of multifunctional composite paper (PTCF/GON) with excellent electromagnetic interference shielding, antibacterial and sound absorption properties was fabricated using surface modified CF (TCF/GON) and plant fibers. The increased active groups on the surface of TCF/GON improved its hydrophilicity and enhanced its dispersibility in water, which facilitated to form an effective interconnected conductive network of composite paper via traditional wet forming process. Composite paper fabricated by 30 wt% surface decorated CF (PTCF1.5/GON1.2) achieved an electromagnetic interference shielding effectiveness as high as 43.4 dB in X-band, shielding 99.9 % of incident electromagnetic energy. Meanwhile, PTCF1.5/GON1.2 exhibits good sound absorption performance in specific frequency bands, with a sound absorption coefficient of 0.98 around 1180 Hz. Besides, PTCF1.5/GON1.2 also exhibited excellent antibacterial properties. This strategy provides an economical and practical method for manufacturing multifunctional electromagnetic shielding materials with superior performance.

Stretchable liquid metal grid/metallized polyurethane composites with switchable electromagnetic interference shielding and efficient infrared stealth performance

Intelligent electromagnetic interference (EMI) shielding materials with tunable electromagnetic shielding properties becomes a significant and urgent concern for information society. Hence, a switchable and low-reflectivity EMI shielding composite is fabricated by electroless nickel plating on the surface of polyurethane nonwoven fabric (Ni@TPU), and followed by combining with liquid metal (LM) grid. The synergistic combination of Ni@TPU and LM grid effectively facilitates the rational construction of hierarchical impedance matching. Meanwhile, it promotes destructive interference between electromagnetic waves reflected from Ni@TPU and the LM grid. As a result, an excellent low-reflectivity EMI shielding performance can be achieved. More importantly, the switchable EMI shielding performance can be easily realized by repeatedly stretching Ni@TPU/LM. In addition, the fluffy nonwoven fabric and LM grid with low infrared emissivity endow it with an outstanding infrared stealth performance. Such excellent low-reflectivity EMI shielding switch performance incorporated with flexible infrared stealth makes it possible to become smart EMI shielding material with a great promise to be employed in the application scenario of window in camouflage container.

Supercritical N2 induced sandwich type lightweight and strong PP/CF foams with excellent electromagnetic shielding properties

The tremendous advances in communication technology and the explosion of electronic products led to an intensification of electromagnetic pollution, yet the efficient development of lightweight, high-strength fiber composite foams with excellent electromagnetic shielding properties was still a great challenge. Herein, this study, inspired by the sandwich structure, proposes a green foaming method with supercritical N2 to prepare a multilayered structure of carbon fiber reinforced polypropylene (PP/CF) foams, with a dense cellular structure in the core layer and a solid layer in the surface layer. The incorporation of CF improves the crystallization and rheological behavior of PP/CF, which guarantees a fine, dense and uniform cellular structure. This inner fine cellular structure and the solid layer on the surface contribute to the excellent mechanical properties. PP/30 %CF foam with a 1 mm mold opening distance displays an enhancement of 189.9 % in tensile strength and 196.3 % in flexural strength compared to pure PP. This also indicates more lightweight, high-strength and high-rigidity microcellular parts was obtained with less raw materials. Moreover, the formation of CF conductive network and internal foam structure contribute to excellent electromagnetic interference (EMI) shielding performance. The PP/CF composite foams maintain a level of EMI shielding performance greater than 30 dB despite the higher mold opening distance. Specifically, the PP/30 %CF foams at opening distance of 5 mm was enhanced to 58.3 dB·cm3/g with an improvement of 76.7 %. This implies that lightweight microcellular parts with both excellent strength and EMI shielding properties can be prepared, which enables PP/CF foams to possess a wide range of applications in various fields.

Highly stretchable and strain-insensitive multilayered electromagnetic interference shielding films prepared via a simple soaking-infiltration strategy

Stretchable electromagnetic interference (EMI) shielding films are crucial for wearable electronics. However, it is challenging to further endow the EMI shielding films with good stretchability and satisfactory EMI shielding effectiveness (EMI SE) under large strains. Herein, we successfully prepared high-performance stretchable polydimethylsiloxane (PDMS)/ single-walled carbon nanotube buckypaper (SWNT BP)/PDMS EMI shielding films with multi-graded conductive networks via a soaking-infiltration strategy. In this multilayered film, infiltration layers of SWNT/PDMS were particularly created between elastic PDMS and brittle SWNT BP. Owing to the multilayered structure and conductivity compensation effects arising from infiltration layers, our EMI shielding films exhibited excellent EMI SE of 34.2 dB with high stretchability of >400%. The outstanding EMI SE could be well maintained under large strains. At <50% strain, the relative change in EMI SE (|ΔSE/SE0|) remained consistently below 10%, while at even 100% strain, |ΔSE/SE0| was only ∼35%. Furthermore, we proposed a parallel-series hybrid model to describe electrical conduction in straining films. Due to their excellent conductivity under strain, the films could also serve as stretchable Joule heaters. This work provides a novel and simple approach for constructing strain-insensitive conductive films, with potential applications in stretchable EMI shielding and thermal management.

Interfacial metallization in segregated structured PEEK composite for enhanced thermal conductivity and electromagnetic interference shielding1

The increasing integration of electronic devices has created an urgent demand for multi-functional composites with efficient thermal management and electromagnetic interference (EMI) shielding. In this study, a three-dimensional (3D) continuous metal–carbon hybrid thermally/electrically conductive network structure is fabricated by in-situ nickel plating of core–shell structured polyetheretherketone (PEEK) hybrid particles. The hybrid particles realise phonon and electron dual heat-transfer pathways and reduce the interfacial thermal resistance by using metallic Ni nanoparticles to bridge the gap. Furthermore, the interfacial metallization and segregated structure significantly enrich the multiple electromagnetic wave reflection and attenuation mechanisms. The PEEK composites with metallized-segregated structure and filler content of 28.26 vol% exhibit an excellent through-plane thermal conductivity of 6.52 W·m–1·K–1 and an efficient EMI shielding of 91 dB, thus demonstrating their significant potential as multi-functional thermal management materials. The heat-transfer and EMI shielding process of the composites can be visualised using the finite element model, which further proves the effectiveness of the segregated structure and metallization. This simple and efficient strategy is expected to facilitate the manufacture of multi-functional thermal management composites with high thermal conductivity and excellent EMI shielding.

High-Performance Flexible Pressure Sensor with Micropyramid Structure for Human Motion Signal Detection and Electromagnetic Interference Shielding.

Flexible pressure sensors have a wide range of applications in the field of human motion signal detection, but the electromagnetic radiation generated during the monitoring process has become an unavoidable problem. Nowadays, it is still a challenge to develop high-performance pressure sensors with excellent electromagnetic interference (EMI) shielding performance. Herein, the Ti3C2TX MXene/carbon fiber/multiwalled carbon nanotube/polydimethylsiloxane (MXene/CMP) films with a micropyramidal structure were developed by the technology of vacuum high-temperature hot pressing and spray deposition. Benefiting from the dielectric loss of the conductive fillers and the presence of the microstructure, the MXene/CMP film exhibits excellent EMI shielding performance, and the EMI shielding efficiency (SE) can reach 49.37 dB. Besides, the introduction of CF effectively improves the mechanical properties of the MXene/CMP films, and the MXene nanosheets deposited on the surface of the film can reduce stress concentration, which in turn delays the expansion of cracks. Furthermore, the MXene/CMP sensor exhibits high sensitivity (89.76 kPa-1) and fast response/recovery time (61/60 ms). The deformation of microstructure and the construction of conductive networks enable the sensor to realize the monitoring of human motion signals (such as finger bending, knee bending, wrist bending, etc.). Meanwhile, the sensor maintains sensing stability even after 2000 pressure cycles, which can be attributed to the improvement in mechanical properties. In summary, the developed high-performance flexible pressure sensor with micropyramid structure has great application prospects in wearable devices and healthcare.

Yarn-Based Degradable Janus PPDO Fabric for Multifunctional Applications.

The growing high standard of people's wear has put forward requirements for fabrics, and multifunctional fabrics have been developed precisely in response to the requirements of the times. However, the incineration of waste fabrics produces a large amount of pollutants, resulting in a massive waste of resources and environmental pollution. Herein, the degradable nanofiber yarns (NYs) with self-cleaning properties were fabricated by in situ growth of SiO2 nanoparticles on the surface of the electrospun poly(p-dioxanone) (PPDO) NYs using the Stöber method. Then, the PPDO NYs were blended with carbon fibers and the PPDO/SiO2 NYs with themselves to form the Janus PPDO fabrics, respectively. The Janus PPDO fabric offered asymmetric wettability and dual personal thermal management properties. The PPDO/C side of the Janus PPDO fabric provided 65.8 °C at 1.5 V or 58.5 °C under one sunlight intensity for radiative heating. The PPDO/SiO2 side exhibited high solar reflectivity (81.8%) and mid-infrared (MIR) emissivity (99.1%), which reduced the skin temperature by 4.6 °C, resulting in radiative cooling. Moreover, the Janus PPDO fabrics display an excellent electromagnetic interference (EMI) shielding performance (53.3 dB). Therefore, yarn-based degradable Janus fabric has a promising future in multifunctional wearable products.

Preparation and Characterization of Lightweight Carbon Foam Derived From Silicon‐Containing Arylacetylene Resin With Antioxidant Properties and Excellent Electromagnetic Interference Shielding Performance

ABSTRACTIn this study, carbon foam derived from silicon‐containing arylacetylene resin (CFPSA) was prepared by using silicon‐containing arylacetylene (PSA) resin as the carbon precursor and polyurethane (PU) foam as the organic sacrificial template. CFPSAs with diverse apparent densities were prepared through the simple impregnation of PU foam with PSA resin solutions of varying concentrations. Their structures, such as the pore morphology; chemical composition; thermal stability; compression properties, and electromagnetic interference (EMI) shielding effectiveness (SE), were characterized. The results indicate that with an increase in the PSA resin concentration, the skeleton of CFPSA becomes thicker, the pore size slightly increases, the apparent density increases, the compressive strength increases, and the EMI SE slightly reduces. CFPSA‐10's apparent density is 0.032 g/cm3, its 5% thermal weight loss temperature (Td5) in an air atmosphere is 642°C, its thermal conductivity is 38.1 mW/m K, its specific compression strength is 2.45 MPa/g cm3, and its specific EMI SE divided by thickness (SSE/t) is 2367 dB cm2/g. CFPSA exhibits lightweight and antioxidant properties, as well as excellent electromagnetic interference shielding performance, presenting great potential for application in aerospace and other fields.

Epoxy microlattice with simultaneous self-sensing and electromagnetic interference shielding performance by in-situ additive manufacturing

The development of epoxy nanocomposite architectures capable of self-sensing the internal structural response to mechanical stimuli and exhibiting multifunctionality represents a significant challenge to the scientific community. Here, an in-situ additive manufacturing technique is developed to construct robust SiO2/epoxy host material and piezoresistive nanocarbon/epoxy sensing elements into an engineered 3D microlattice. The integration of microscale sensing elements with tailored embedment locations and contents enables the real-time detection of in-situ strain under varying loadings, without compromising the mechanical properties of the original host structure. Additionally, the epoxy microlattices containing 3D interconnected network of sensing elements present excellent electromagnetic interference shielding properties, attaining a high shielding effectiveness of up to 33 dB. Furthermore, the applications of the epoxy microlattice in defect-recognizable composite lattices and multifunctional protective devices are demonstrated. The present findings suggest an effective strategy for the development of intrinsically smart epoxy nanocomposites with customized microstructure and unprecedented multifunctionality.

Flexible, transparent, and low-temperature usable electromagnetic shielding film based on orthogonally arranged silver nanowire network/graphene oxide conductive network

With the increasing diversification of application environments of new electronic products, demands are being placed on flexibility, transparency, and stable operation capability even under harsh conditions of electromagnetic shielding films. Aiming at the issue of high contact resistance of simple silver nanowire (AgNWs) conducting network, this work utilizes orthogonally arranged AgNWs and graphene oxide (GO) to establish unique AgNWs/GO conductive network, achieving more conductive nodes and enhancing the stability of the conductive network. The resulting AgNWs/GO film exhibits a reduced resistance of 9.8 Ω/sq, an impressive light transmittance of 85.7 % (λ = 550 nm), and excellent electromagnetic interference shielding efficiency (EMI SE) reaching 30.3 dB in the X-band (8.2–12.4 GHz). Moreover, the AgNWs/GO film exhibits the potential for long-term operation in harsh environments. After undergoing numerous bending cycles (10,000 times), prolonged exposure (90 days), and repeated energization (800 times), the resistance of the AgNWs/GO film remains extremely stable. Furthermore, the film demonstrates remarkable electrothermal conversion capability in cold environments, rapidly heating to 73.3 ℃ under a 4 V voltage and maintaining stability thereafter. After 800 h of operation, there is negligible change in its electrothermal properties. The development of such a flexible electromagnetic shielding film holds significant implications for various applications.

Silver nanoparticles bridging liquid metal for wearable electromagnetic interference fabric

Stretchable conductive fibers are essential for the advancement of wearable electronic textiles. However, a significant challenge arises as their conductivity sharply decreases when stretched due to disruptions in electronic transport. Coating fibers with soft liquid metal (LM) has emerged as a promising solution. Despite this, there remains an urgent need to develop methods that enhance LM adhesion to substrates while facilitating efficient electron transport pathways. This study demonstrates a novel Ag-LM conductive network strategy for fabricating a thermoplastic polyurethane/polydopamine/silver-LM (TPU/PDA/Ag-LM) fiber membrane. This membrane exhibits outstanding stretchable electromagnetic interference (EMI) shielding performance and is produced through straightforward electrospinning, electroless depositing, and LM coating and activation. The TPU/PDA/Ag fiber membrane is initially prepared via polydopamine-assisted deposition of silver nanoparticles (AgNPs) on electrospun TPU fibers. The presence of AgNPs on the surface of TPU/PDA fibers enhances LM adhesion to the substrate and bridges adjacent LM to establish efficient conductive paths. This interaction benefits from the reactive alloying between AgNPs and LM, where the LM infiltrates the gaps among AgNPs, forming a distinctive LM-Ag alloy layer that uniformly coats the surface of TPU fibers. As anticipated, the unique three-dimensional (3D) interconnected LM-Ag conductive network remains intact during stretching, ensuring strain-invariant conductivity. The fabricated TPU/PDA/Ag-LM fiber membrane demonstrates exceptional EMI shielding effectiveness (SE) of 77.4 dB within the frequency range of 8.2–12.8 GHz and maintains an excellent EMI SE of 37.2 dB under extensive tensile deformation of 300%. Furthermore, the TPU/PDA/Ag-LM fiber membrane shows remarkable mechanical properties and stable Joule heating performance even under significant stretching.

Interfacial enhancement enables highly conductive reduced graphene oxide-based yarns for efficient electromagnetic interference shielding and thermal regulation

Although the coating of conductive graphene onto commercial yarns is promising for scalable production, the resulting conductive yarns are susceptible to the coating detachment, causing reduced conductivity and poor stability. Herein, we propose a scalable and cost-effective interfacial enhancement strategy for fabricating highly conductive yarns with satisfactory mechanical properties by modifying polyamide yarns with polyethyleneimine to enhance their interaction with graphene oxide (GO) sheets and subsequently reducing the GO component with hydroiodic acid. Because the enhanced interfacial interactions of the polyethyleneimine-modified polyamide yarns with the GO sheets improve the loading of GO and the coating stability, the resultant yarns can withstand bending, embroidering, sewing and weaving, maintaining an extraordinary conductivity of 4.7 × 103 S m−1 after 10000-cycle bending. The conductive textiles woven by the yarns reach an excellent electromagnetic interference (EMI) shielding effectiveness of 66.7 dB at the thickness of 0.615 mm along with superior hydrophobicity, satisfactory air permeability, and high electrothermal and solar-thermal energy conversion performances. The EMI shielding effectiveness of the textile is well maintained even after 5000-cycle bending, demonstrating its satisfactory stability. This work demonstrates an interfacial enhancement strategy for the large-scale fabrication of multifunctional yarns that hold great promise for EMI shielding, personal thermal regulation, and deicing applications.

Effect of La content on mechanical properties and electromagnetic interference shielding effectiveness of Mg-Zn-Y-La-Zr alloy

In recent years, a great demand exists for Mg alloy materials that combine excellent mechanical properties and electromagnetic interference shielding effectiveness (EMI SE). In this study, the effects of La content on the microstructure, mechanical properties, and EMI SE of Mg-6Zn-1Y-xLa-0.5Zr alloys are reported in detail. The microstructures of Mg-6Zn-1Y-xLa-0.5Zr alloys treated by extrusion all exhibit bimodal microstructure characteristics. Mg-6Zn-1Y-1.0La-0.5Zr alloys show a superior balance between mechanical properties and EMI SE. The UTS, YS, and elongation were 332.3 MPa, 267.3 MPa, and 16.2 %, respectively. Meanwhile, the EMI SE in the frequency range of 30–1500 MHz is 79–110 dB, and the excellent mechanical properties are due to the combined effect of fine-grain strengthening, second-phase strengthening, and heterogeneous structure strengthening. The excellent EMI SE is mainly attributed to the dense and diffusely distributed second phase providing more interfaces that can reflect electromagnetic waves.

Bi-functional flexible Ag2Se/Polyvinylidene fluoride composite films for thermal energy conversion and electromagnetic interference shielding by solution 3D printing

Developing bi-functional thermoelectric (TE) and electromagnetic interference (EMI) shielding materials is an effective way for the integrated electronic devices to face the accumulated thermal energy and complicated electromagnetic environment. Herein, flexible Ag2Se/polyvinylidene fluoride (Ag2Se/PVDF) composite films were successfully prepared through solution 3D printing and subsequent annealing treatment. As Ag2Se content increased, both the power factor and average total EMI shielding effectiveness (SET) were boosted. When the mass fraction of Ag2Se was 85 wt%, a power factor of 904.6 μW m−1K−2 at 360 K was achieved for the ASP-85 composite film. Meanwhile, this ASP-85 composite film shown the outstanding SET value of 56.1 dB at 52 μm thickness. Flexible Ag2Se/PVDF composite films displayed the excellent thermal energy conversion and EMI shielding capacity.

3D printed SiOC architecture towards terahertz electromagnetic interference shielding and absorption

Electromagnetic interference (EMI) shielding and absorption materials can effectively mitigate the undesired pollution or noise caused by terahertz (THz) waves. The development of THz EMI shielding materials that are primarily based on absorption mechanisms to avoid secondary pollution caused by reflection is still in big demand. Herein, an absorption-dominated precursor-derived SiOC ceramic (PDC-SiOC) architecture for THz wave EMI shielding and absorption was reported. The EMI shielding properties of the bulk SiOC ceramic were studied. More than 93 % of THz EM waves were absorbed by the synthesized SiOC ceramic from 1.2 to 1.6 THz. Furthermore, lightweight honeycomb-structured SiOC architecture which was inspired by the wings of moth was fabricated by vat photopolymerization 3D printing combined with following pyrolysis. The EMI shielding properties and mechanism of the honeycomb SiOC architecture in THz bands were also discussed. The highest shielding effectiveness (SE) of the honeycomb SiOC architecture was up to 64.1 dB, and the transmissivity was below 1.4 % from 0.2 to 1.6 THz. In addition, more than 97–99.8 % of THz waves were absorbed in 0.8–1.6 THz. The excellent EMI shielding performance of the architecture was mainly attributed to its outstanding THz EM wave absorption ability. Finally, the mechanical properties and thermal stability of the architecture were further studied. The compressive and flexural strength of honeycomb architecture was 1.2 and 16.5 MPa, respectively. The result also proved that the honeycomb SiOC architecture was resistant to high temperatures up to 1100 °C under inert atmosphere. This work provides promising high-efficiency architecture towards THz EMI shielding and absorption.

Flexible solid-liquid bi-continuous electrically and thermally conductive nanocomposite for electromagnetic interference shielding and heat dissipation

In the era of 5 G, the rise in power density in miniaturized, flexible electronic devices has created an urgent need for thin, flexible, polymer-based electrically and thermally conductive nanocomposites to address challenges related to electromagnetic interference (EMI) and heat accumulation. However, the difficulties in establishing enduring and continuous transfer pathways for electrons and phonons using solid-rigid conductive fillers within insulative polymer matrices limit the development of such nanocomposites. Herein, we incorporate MXene-bridging-liquid metal (MBLM) solid-liquid bi-continuous electrical-thermal conductive networks within aramid nanofiber/polyvinyl alcohol (AP) matrices, resulting in the AP/MBLM nanocomposite with ultra-high electrical conductivity (3984 S/cm) and distinguished thermal conductivity of 13.17 W m−1 K−1. This nanocomposite exhibits excellent EMI shielding efficiency (SE) of 74.6 dB at a minimal thickness of 22 μm, and maintains high EMI shielding stability after enduring various harsh conditions. Meanwhile, the AP/MBLM nanocomposite also demonstrates promising heat dissipation behavior. This work expands the concept of creating thin films with high electrical and thermal conductivity.

Emulsion-Based Multiscale Structural Design Realizes Lightweight and Superelastic Graphene Aerogels for Electromagnetic Interference Shielding.

Ultralight graphene aerogels with high electrical conductivity and superelasticity are demanded yet difficult to produce. A versatile emulsion-based approach is demonstrate to optimize multiscale structure of lightweight, elastic, and conductive graphene aerogels. By constructing Pickering emulsion using graphene oxide (GO), poly (amic acid) (PAA), and octadeyl amine (ODA), micron-level close-pore structure is realized while thermal shrinkage mismatch between GO and PAA creates numerous nanowrinkles during thermal annealing. GO nanosheets are bridged by PAA-derived carbon, enhancing the structural integrity at molecular level. These multiscale structural features facilitate rapid electron transport and efficient load transfer, conferring graphene aerogels with intriguing mechanical and electromagnetic interference (EMI) shielding properties. The emulsion-based graphene aerogel with an ultralow density of ≈3.0mg cm-3 integrates outstanding electrical conductivity, air-caliber thermal insulation, high EMI shielding effectiveness of 75.0dB, and 90% strain compressibility with superb fatigue resistance. Intriguingly, thanks to the gel-like rheological behavior of the emulsion, ultralight graphene scaffolds with programmable geometries are obtained by 3D printing. This work provides a general approach for the preparation of ultralight and superelastic graphene aerogels with excellent EMI shielding properties, showing broad application prospects in various fields.

High‐efficiency electrothermal and electromagnetic interference shielding performance of expanded graphite/silicone film

AbstractExpanded graphite (EG) is a desired filler for electrothermal and electromagnetic interference (EMI) shielding because of its easy access, low‐cost, lightweight, high conductivity, and heat sensitivity. Herein, fluffy EG was prepared from natural flake graphite (NFG) by a simple expansive technology and subsequently heat treatment at 800°C for 2.0 h in 5% Ar/H2 atmosphere. EG/silicone films with a filling ratio of 15 wt% were obtained via hot‐pressing, which exhibited sensitive electrothermal and excellent EMI shielding performances. When the applied voltages were 5.0, 10.0, and 15.0 V, the steady‐state temperatures were 54.0, 136.5, and 237.8°C in the 30s, respectively. Meanwhile, their average EMI shielding efficiency was greater than 20 dB in 2–18 GHz at 0.84 mm, which was 6.3 times as much as NFG/silicone film. Therefore, this study offers a simple and effective strategy for preparing excellent electrothermal‐EMI shielding materials.Highlights Fluffy EG is prepared by a simple expansive method and treatment at 800°C. EG/silicone films exhibit good electrothermal and EMI shielding performances. Steady temperatures of 55.0/136.5/237.8°C are gotten at 5/10/15 V in 30 s. The EMI shielding efficiency is greater than 20 dB at 0.84 mm. Good properties are due to the EG with high conductivity and fluffy structure.

Construction of rGO-MXene@FeNi/epoxy composites with regular honeycomb structures for high-efficiency electromagnetic interference shielding

With the rapid development of 5G communication technology and wearable electronic devices, the demand for low-reflection electromagnetic interference (EMI) shielding materials is becoming increasingly urgent. In this work, reduced graphene oxide-MXene (rGMH) @FeNi/epoxy EMI shielding composites with a regular honeycomb structure were successfully prepared by the combination of surface functionalization modification, sacrificial template, and freeze-drying. The effects of magnetic FeNi alloy particle loading mode and loading amount on the EMI shielding performance of composites were investigated. The results show that rGMH@FeNi/epoxy EMI shielding composites have the highest EMI shielding effectiveness (EMI SE) and the lowest reflection shielding effectiveness when magnetic FeNi alloy particles are loaded only on the graphene skeleton. In this composite, the EMI SE value of the composite is 61 dB when the rGMH@FeNi mass fraction is 5.4 wt% (f-FeNi mass fraction is 0.9 wt%), which is 4.7 times that of the blended rGO/MXene/FeNi/ epoxy resin composite (13 dB) with the same mass fraction. At the same time, the rGMH@FeNi/epoxy composite has excellent thermal stability (heat-resistance index of 190.3 °C) and mechanical properties (energy storage modulus of 8606.7 MPa). These polymer-based EMI shielding composites with excellent EMI shielding properties and low reflection effectiveness have great potential in the protection of high-power, portable and wearable electronic devices against electromagnetic pollution.