Electromagnetic Interference Shielding Properties 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.

Ultra-high strength and flame retardant carbon aerogel composites with efficient electromagnetic interference shielding and superior thermal insulation via nano-repairing route

Carbon aerogel composites (CAs) have received numerous attention for protection of aircraft due to their unique properties. However, the shrinkage mismatch between rigid fibers and carbon sources during carbonization dramatically weakens the performance of CAs, and no significant breakthroughs have been made. We propose a vacuum impregnation assisted nano-repairing (VINR) strategy to fabricate crack-free carbon fiber reinforced carbon aerogel (Cf/CA) composites with high strength, electromagnetic interference shielding and thermal insulation. The cross-confined, overlapping nano-CA particles greatly limits the shrinkage of the carbon source, conferring excellent mechanical properties to Cf/CA, and its compressive strength and modulus reaches 3.93 MPa and 69.96 MPa in XY direction and 2.03 MPa and 40.67 MPa in Z direction, respectively, at 5 % strain. In addition, Cf/CA exhibits significant thermal insulation (0.054 W/(m·K) at 25 °C under air condition) and superior electromagnetic interference shielding properties (EMI SE is ∼48.52 dB at a thickness of ∼2 mm). Herein, the structurally optimized Cf/CA provides a promising solution for multi-effect protection for critical electronic devices of aircraft in special service environments.

Poly(Vinylidene Fluoride‐Hexafluoropropylene) Composites With Carbon Based Nanofillers for Electromagnetic Interference Shielding

ABSTRACTIn the current work, a series of flexible polymer matrix composites (PMCs) based on poly(vinylidene fluoride‐hexafluoropropylene) (PVDF‐HFP) as the polymer matrix and carbon nanofillers, namely single‐walled nanotubes (SWCNT) or carbon blacks (CB), were fabricated via a facile preparation method of blending and solution casting. The electrical conductivity, morphology, dielectric constant, mechanics, and electromagnetic interference (EMI) shielding properties of the composite films were adjusted by varying the carbon type (CB = Ketjenblack, Vulcan, or SWCNT = Tuball) and amount (0.1–15 wt%). The influence of the conductive nanofillers on the EMI shielding effectiveness (SE) and microwave absorbing properties in the X‐band frequency range (8–12 GHz) were investigated. By increasing the carbon content, the EMI shielding properties of the composite films were improved due to an increase in the magnitude of the electromagnetic properties. As the loading of these carbon fillers approach the percolation threshold, the dielectric constant of the composite can dramatically increase because of the construction of a microcapacitor network. However, these nanofillers/polymer composites generally have high dielectric loss near the percolation threshold due to the direct connection between carbon nanofillers. The PVDF‐HFP/Tuball composite particularly contributed low dielectric loss to the electromagnetic (EM) wave, resulting in excellent microwave absorption properties with a SE per unit thickness of 337.5 dB/mm and 2.5× less weight compared with conventional aluminum with the same SE, demonstrating the promise of using these materials as practical EMI shields.

Structure‐function integrated design of electromagnetic interference shielding and mechanical properties of 2D carbon fiber reinforced polymer composites based on absorption loss regulation

Structure‐function integrated design of electromagnetic interference shielding and mechanical properties of <scp>2D</scp> carbon fiber reinforced polymer composites based on absorption loss regulation

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.

Role of Pb(Zr0.52Ti0.48)O3 on Electric, Dielectric, Electromagnetic Wave Absorption Characteristics of Multiferroic Nanocomposites for Magnetoelectric Devices

Multiferroic composites of ferrite and ferroelcectric phases with systematically varying concentration (100-x)Mg0.48Cu0.12Zn0.4Fe2O4 + x Pb(Zr0.52Ti0.48)O3 (MCZPZT) ( where, x mol% = 0, 20, 40, 50, 60, 80, 100) were prepared by mechanical alloying and sintering methods. The dc resistivity and dielectric constant of the samples as a function of temperature were studied in detail and obtained results are reported. The magnetoelectric effect was investigated for the composites. The sample with 80% ferroelectric phase (MP5), shows largest magnetoelectric output voltage coefficient (dE/dH) H value of 880 μVcm.Oe at 2000 Oe magnetic field. Electromagnetic interference shielding properties of transmission loss and attenuation constant were determined for the composites. Skin depth decreases with frequency from 0.29 to 0.2 cm in the range 8–12 GHz for all composites. The composite MP5 with 80% PZT shows lowest α value between 282 dB m−1 and 414 dB m−1 throughout X-band frequencies. The present results proved that the current magnetoelectric materials of all concentrations exhibit strong magnetoelectric coupling with excellent microwave absorbing performance in X-band region and are appropriate for EMI shielding and novel device applications.

Spin-coating ANF based multilayer symmetric composite films for enhanced electromagnetic interference shielding and thermal management

The demand for flexible composite films with electromagnetic interference (EMI) shielding capabilities is rapidly increasing. Balancing high EMI performance with flexibility and portability has become a critical research focus in practical applications. In this study, an optimized strategy for aramid nanofibers (ANF) films was developed using spin-coating and sol–gel techniques. The resulting film features a smooth surface and excellent mechanical properties. ANF, initially an insulator, was transformed into a conductor through the in-situ polymerization of ion-doped polypyrrole (PPy). Leveraging a multilayer structural strategy, we prepared a symmetric composite film, ANF@PPy-(TA-MXene)-AgNWs-(TA-MXene)-ANF@PPy (PMA), using vacuum-assisted filtration and lamination hot pressing. This film, composed of ANF@PPy (PA) as the matrix, tannic acid (TA) modified MXene, and silver nanowires (AgNWs) as fillers, exhibited multiple shielding mechanisms as electromagnetic wave (EMW) passed through its various layers. This multilayer configuration provides significant flexibility in EMW shielding. Moreover, TA-modified MXene expands the lamellar spacing, enhancing the scattering efficiency of EMWs within the film, and serves as a medium connecting the upper and lower layers. This results in the efficient integration of the multilayer structure, synergistically improving both EMI shielding performance and mechanical properties. When the ratio of PA/MXene/AgNWs was 1:3:1, the film demonstrated optimal properties, including an EMI shielding effectiveness of 70.2 dB, thermal conductivity of 4.62 W/(m•K), and tensile strength of 50.2 MPa. Due to the exceptional EMI shielding and thermal properties of the PMA composite film, it holds great potential for applications in artificial intelligence, wearable heaters, and military equipment.

Electromagnetic interference shielding properties of foamed SiCnws/SiC composites reinforced by in-situ grown carbon nanofibers

Interwoven network structures composed of one-dimensional nanomaterials with excellent dielectric properties present promising potential for application in the field of electromagnetic interference (EMI) shielding. In this work, the disordered carbon nanofibers (CNFs) are in-situ grown on the interconnected silicon carbide nanowires (SiCnws) aerogel by chemical vapor infiltration (CVI), which is foamed by unidirectional freeze casting. Subsequently, the SiC interface is deposited to construct an engagement of CNFs and SiCnws. Arising from the penetrating structure, the average total EMI shielding efficiency (SET) of the SiCnws/CNFs/SiC composites increases from 28.9 dB to 42.8 dB in X band with just 2 mm thickness. Moreover, the maximum SET value of the composites can be up to 57.2 dB, indicating more than 99.999 % of microwaves will be shielded. The excellent EMI shielding performance can be attributed to integrating multiple loss mechanisms such as conductivity loss, interface polarization loss, and dipole polarization loss. The integrated lightweight composites provide a new design routine for electromagnetic shielding structure components.

Hybrid-structured carbon fiber fabric/silk fiber non-woven fabric/carbonyl iron powder/epoxy composites with highly efficient electromagnetic interference shielding and mechanical properties

In this study, carbonyl iron powder (CIP) was loaded onto the surfaces of carbon fiber fabric (CF) and silk non-woven fabric (SF) through a spraying process and surface micro-dissolve & adhesion (SMDA) process, respectively. Subsequently, CF/SF/CIP reinforced epoxy (CF/SF/CIP/EP) composites with different hybrid structures were fabricated using vacuum-assisted resin transfer molding (VARTM) technique. The effects of these hybrid structures on both the electromagnetic interference (EMI) shielding performance and mechanical properties of the composites were systematically assessed. The results reveal that with an increase in the layer fraction of CF, the mechanical properties of the modified hybrid fibers (HFs) composites demonstrate a positive hybrid effect. Particularly noteworthy is the observation that when the layer ratio of CF to SF is maintained at 1:1, the M-CSCS/EP composites featuring an interlayer hybrid structure exhibit the highest EMI shielding effectiveness of 34.9 dB within the X-band of 8.2–12.4 GHz. This enhancement is attributed to the improved interfacial polarization loss capability of incident electromagnetic waves, facilitated by the increased two-phase interface formed between CF and SF. Moreover, the composite exhibits excellent mechanical properties, including a tensile strength of 339.9 MPa, interlaminar shear strength of 32.1 MPa, and impact strength of 98.2 kJ/m2. Consequently, the HFs composites developed in this study offer a commendable balance between EMI shielding performance and mechanical properties, rendering them highly suitable for a wide array of applications in aerospace, rail transportation, and communication equipment.

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.

Electromagnetic interference shielding properties of PMMA modified-Co0.5Zn0.5Fe2O4 − polyaniline composites

Present work reports solution combustion synthesis (SCS) of Co0.5Zn0.5Fe2O4 spinel ferrite, its chemical modification with polymethylmethacrylate (PMMA), synthesis of polyaniline (PANI), and electromagnetic interference (EMI) shielding properties of their composites. Both as-prepared and PMMA-modified Co0.5Zn0.5Fe2O4 adopt cubic spinel structure as shown by X-ray diffraction studies. Field emission scanning electron microscopy images show the agglomerated and microporous nature of the ferrites. High resolution transmission electron microscopy image of as-prepared Co0.5Zn0.5Fe2O4 shows lattice fringes related to (311) plane of the spinel structure. X-ray photoelectron spectroscopy studies reveal the presence of Co2+, Zn2+, and Fe3+ in tetrahedral and octahedral coordinations in the ferrite. EMI shielding properties are evaluated for PMMA-modified Co0.5Zn0.5Fe2O4 and PANI composites in different weight ratios. Composites containing PMMA-modified ferrite and PANI with 50:50 and 10:90 weight ratios show the best performance among all the composites in 2−20 GHz frequency range. Optimized PMMA-modified Co0.5Zn0.5Fe2O4 and PANI composite with the ratio of 10:90 shows shielding effectiveness (SE) values of −16.6 to −24.2 dB in 2−20 GHz frequency region.Graphical

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.

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.

Electromagnetic Interference Shielding Properties of SrFe12-2x(Cu0.5Co0.5Ti)xO19 Hexaferrite

Electromagnetic (EM) pollution has become one of the most severe forms of pollution for humans and electronic devices. In order to protect humans and electronic devices from electromagnetic interference (EMI), the material that could shield the EMI should be considered. Hexagonal ferrites are considered as promising candidates for EMI shielding materials. This work fabricated Cu, Co, and Ti co-doped SrFe12O19 (SrFe12–2x(Cu0.5Co0.5Ti)xO19) samples to investigate EMI shielding properties. Among the samples, the doped ones exhibited better EMI shielding performance than the undoped one, which could be judged through total shielding efficiency (SET). In addition, the samples exhibited the best shielding performance in the frequency range of 8–12 GHz (X-band), with the best value of SET = 4.20 dB for the x = 0.20 sample, which could block ~62% of the incident microwave. The x = 0.05 sample also exhibited similar values with SET = 4.17 dB. The enhancement of SET values for doped samples compared to the undoped one could be attributed to the increase in conductivity caused by doping. In addition, the enhancement of SET could also be attributed to the effects of the magnetic dipoles combined with the electric dipoles of ferrites.

Electromagnetic interference shielding behavior of flexible PVA composite made using betel nut husk biocarbon and steel microwire in E, F, I, and J band spectrum

AbstractThis study investigates the electromagnetic interference (EMI) shielding behavior of a flexible polyvinyl alcohol (PVA) composite fabricated using betel nut husk biocarbon and steel microwire in the E, F, I, and J band spectrum. The incorporation of steel microwire into the PVA based composite is novel approach since it provides flexibility along with good mechanical strength. The fabrication process involves the solution casting method, and the composite is characterized according to American society of testing and materials (ASTM) standards. The research focuses on analyzing dielectric behavior, EMI shielding effectiveness, and mechanical properties. Results indicates that, the composite with 5 vol.% of biocarbon and 5 vol.% of micro metal wire, exhibits exceptional relative permittivity of 7.6, 6.9, 6.3, and 1.5 for E, F, I, and J frequency bands and same composition delivers exceptional electromagnetic shielding with total shielding values of 17.7 dB, 25.5 dB, 31.7 dB, and 38.6 dB for E, F, I, and J frequency bands. In mechanical characteristics, composite with 5 vol.% of biocarbon and 5 vol.% of micro metal wire, exhibits high tensile strength of 73 MPa with lower elongation percentage of 109.2% and shore‐D hardness of 40, respectively. Thus, the inclusion of betel nut husk biocarbon and steel microwire into the PVA matrix enhanced the overall EMI shielding properties along with mechanical properties. These flexible EMI shielding composites could be used in applications such as defense, telecommunication, drones, and electronic gadget making segments.Highlights Flexible polyvinyl alcohol (PVA) composite is made with steel microwire and betel nut husk biocarbon. Biocarbon is derived from betel nut husk for first time and used as EM wave absorber. Composites were made via simple solution casting method for high flexibility index. Composite contains 5 vol.% biocarbon and 5 vol.% micro metal wire, shows high relative permittivity 7.6 for E frequency bands. The composites have high tensile strength of 73 MPa with a low elongation percentage of 109.2% and a shore‐D hardness of 40.

Electromagnetic Interference (EMI) Shielding and Thermal Management of Sandwich-Structured Carbon Fiber-Reinforced Composite (CFRC) for Electric Vehicle Battery Casings.

In response to the growing demand for lightweight yet robust materials in electric vehicle (EV) battery casings, this study introduces an advanced carbon fiber-reinforced composite (CFRC). This novel material is engineered to address critical aspects of EV battery casing requirements, including mechanical strength, electromagnetic interference (EMI) shielding, and thermal management. The research strategically combines carbon composite components with copper-plated polyester non-woven fabric (CFRC/Cu) and melamine foam board (CFRC/Me) into a sandwich-structure composite plus a series of composites with graphite particle-integrated matrix resin (CFRC+Gr). Dynamic mechanical analysis (DMA) revealed that the inclusion of copper-plated fabric significantly enhanced the stiffness, and the specific tensile strength of the new composites reached 346.8 MPa/(g/cm3), which was higher than that of other metal materials used for EV battery casings. The new developed composites had excellent EMI shielding properties, with the highest shielding effectives of 88.27 dB from 30 MHz to 3 GHz. Furthermore, after integrating the graphite particles, the peak temperature of all composites via Joule heating was increased. The CFRC+Gr/Me reached 68.3 °C under a 5 V DC power supply after 180 s. This research presents a comprehensive and innovative approach that adeptly balances mechanical, electromagnetic, and thermal requirements for EV battery casings.

A Two-Layer Graphene Nonwoven Fabric for Effective Electromagnetic Interference Shielding.

Rapid advancements and proliferation of electronic devices in the past decades have significantly intensified electromagnetic interference (EMI) issues, driving the demand for more effective shielding materials. Herein, we introduce a novel two-layer graphene nonwoven fabric (2-gNWF) that shows excellent EMI shielding properties. The 2-gNWF fabric comprises a porous fibrous upper layer and a dense conductive film-like lower layer, specifically designed to enhance EMI shielding through the combined mechanisms of reflection, multiple internal reflections, and absorption of electromagnetic waves. The 2-gNWF exhibits a remarkable EMI shielding effectiveness (SE) of 80 dB while maintaining an impressively low density of 0.039 g/cm3, surpassing the performance of many existing graphene-based materials. The excellent EMI shielding performance of 2-gNWF is attributed to the multiple interactions of incident electromagnetic waves with its highly conductive network and porous structure, leading to efficient energy dissipation. The combination of high EMI SE and low density makes 2-gNWF ideal for applications that require lightweight yet effective shielding properties, demonstrating the significant potential for advanced EMI shielding applications.

Ultrafine Aramid Nanofiber-Assisted Large-Area Dense Stacking of MXene Films for Electromagnetic Interference Shielding and Multisource Thermal Conversion.

Polymers are often used as adhesives to improve the mechanical properties of flexible electromagnetic interference (EMI) shielding layered films, but the introduction of these insulating adhesives inevitably reduces the EMI performance. Herein, ultrafine aramid nanofibers (UANF) with a diameter of only 2.44 nm were used as the binder to effectively infiltrate and minimize the insulating gaps in MXene films, for balancing the EMI shielding and mechanical properties. Combining the evaporation-induced scalable assembly assisted by blade coating, flexible large-scale MXene/UANF films with highly aligned and compact MXene stacking are successfully fabricated. Compared with the conventional ANF with a larger diameter of 7.05 nm, the UANF-reinforced MXene film exhibits a "brick-mortar" structure with higher orientation and compacter stacking MXene nanosheets, thus showing the higher mechanical properties, electrical conductivity, and EMI shielding performance. By optimizing MXene content, the MXene/UANF film can achieve the optimal tensile strength of 156.9 MPa, a toughness of 2.9 MJ m-3, satisfactory EMI shielding effectiveness (EMI SE) of 40.7 dB, and specific EMI SE (SSE/t) of 22782.4 dB cm2/g). Moreover, the composite film exhibits multisource thermal conversion functions including Joule heating and photothermal conversion. Therefore, the multifunctional MXene/UANF EMI shielding film with flexibility, foldability, and robust mechanical properties shows the practical potential in complex application environments.

Electromagnetic Interference Shielding and Joule Heating Properties of Flexible, Lightweight, and Hydrophobic MXene/Nickel-Coated Polyester Fabrics Manufactured by Dip-Dry Coating and Electroless Plating.

High-performance electromagnetic interference (EMI) shielding materials with high flexibility, low density, and hydrophobic surface are crucial for modern integrated electronics and telecommunication systems in advanced industries like aerospace, military, artificial intelligence, and wearable electronics. In this study, we present flexible and hydrophobic MXene/Ni-coated polyester (PET) fabrics featuring a double-layered structure, fabricated via a facile and scalable dip-dry coating process followed by electroless nickel plating. Increasing the dip-dry coating iterations up to 10 cycles boosts the MXene loading content (∼31 wt %) and electrical conductivity (∼86 S/cm) of MXene-coated PET fabrics, while maintaining constant porosity (∼95%). The addition of a Ni layer enhances hydrophobicity, achieving a high water contact angle of ∼114° compared to only MXene-coated PET fabrics (∼49°). Furthermore, the 30 μm thick MXene/Ni-coated PET fabric demonstrates superior electrical conductivity (∼113.8 S/cm) and EMI shielding effectiveness (∼35.7 dB at 8-12 GHz) compared to only MXene- or Ni-coated PET fabrics. The EMI shielding performance of the MXene/Ni-coated PET fabric remains more stable in an air environment than only MXene-coated fabrics due to the outer Ni layer with excellent hydrophobicity and oxidation stability. Additionally, the MXene/Ni-coated PET fabric exhibits impressive Joule heating performance, swiftly converting electrical energy into heat and reaching high steady-state temperatures (32-92 °C) at low applied voltages (0.5-1.5 V).