Excellent Electromagnetic Shielding Research Articles

The preparation of SiO2/SWCNT@Ni composite film with sandwich structure and its excellent electromagnetic shielding and thermal insulation performances in extreme environment

With the continuous exploration of the extreme environment in space, strong space radiation and extreme high temperature environment have brought great challenges to the research work of astronauts. This study effectively created the SiO2/SWCNT@Ni composite film with electromagnetic shielding and thermal insulation performances by a high-temperature carbon reduction process utilizing the SiO2 nanofiber, the poly(vinyl alcohol) (PVA) solution of single-walled carbon nanotubes (SWCNT), and Ni(NO3)2 as raw ingredients. The adaptable SiO2 nanofiber membrane was synthesized by sol–gel and electrospinning methods utilizing tetraethyl n-silicate hydrolysis precursors as the primary ingredients. At a result, when the content of SWCNT content is 9 wt%, the average EMI SET of SiO2/SWCNT9@Ni is 39.4 dB, and the thermal conductivity measures 0.0405 W/m·K. In addition, SiO2/SWCNT9@Ni shows a good flame-retardant performance. Consequently, this research holds significant reference value in the field of manned spaceflight.Graphical abstractSiO2/SWCNT@Ni composite film with sandwich structure has excellent electromagnetic shielding and thermal insulation performances.

Constructing SiAPP‐NH2@MOFs Core‐Shell Structure Toward Hierarchical Composites With Excellent Flame Retardancy, Smoke Suppression, and Electromagnetic Interference Shielding

ABSTRACTDesigning multifunctional composites with high flame retardancy and excellent electromagnetic shielding performance is of significant importance. In order to address the poor flame retardant and electromagnetic shielding performances of thermoplastic polyurethane (TPU) composites, in this work, the γ‐propyl‐trimethoxysilane (KH550) functionalized silicon microencapsulated ammonium polyphosphate (SiAPP‐NH2) was synthesized using interface modulation technology. Then, SiAPP‐NH2 was combined with a copper metal–organic framework (MOF‐Cu) through microencapsulation and electrostatic self‐assembly techniques to prepare microencapsulated flame retardants (SiAPP‐NH2@MOF‐Cu). Subsequently, TPU composites were prepared through melt blending of SiAPP‐NH2@MOF‐Cu with TPU material. The results showed that the interface interaction between SiAPP‐NH2@MOF‐Cu and the TPU matrix was significantly enhanced. Compared to pure TPU, TPU/5SAN@1MC composite exhibited decreases of 78.7%, 51.3%, 59.3%, and 58.7% in peak heat release rate, total heat release, total smoke release, and total carbon dioxide release, respectively. In addition, TPU/1SAN@1MC/rGO composite achieved an average shielding effectiveness of 13.82 dB in the X‐band, enabling its broad commercial application. This study offers a promising strategy for the fabrication of TPU composites with good flame retardant and electromagnetic shielding properties.

Hierarchical configuration design of PAN/Gr@MWCNTs composite film with superior electromagnetic shielding and excellent Joule heating via in-situ sedimentation strategy

Hierarchical configuration design of PAN/Gr@MWCNTs composite film with superior electromagnetic shielding and excellent Joule heating via in-situ sedimentation strategy

Recyclable polyvinyl alcohol/silvered carbon fiber composite foam with excellent electromagnetic shielding and mechanical stability

Recyclable polyvinyl alcohol/silvered carbon fiber composite foam with excellent electromagnetic shielding and mechanical stability

Polyurethane nickel lacquer coated carbon fiber cloth with excellent mechanical properties and high electromagnetic shielding performance

Polyurethane nickel lacquer coated carbon fiber cloth with excellent mechanical properties and high electromagnetic shielding performance

Fe3O4‐doped highly electromagnetically shielded PAN‐PVP composite porous carbon films

AbstractWith the wide application of modern electronic devices, the problem of electromagnetic pollution is becoming more and more serious, and the demand for efficient electromagnetic shielding materials is becoming more and more urgent. To address this problem, we homogeneously mixed polyacrylonitrile (PAN), polyvinylpyrrolidone (PVP), and triiron tetraoxide (Fe3O4) nanoparticles by solution blending, and prepared composite precursor membranes by taking advantage of the magnetic properties and good electromagnetic loss characteristics of Fe3O4, as well as the high thermal stability and film‐forming properties of PAN and PVP. Subsequently, carbonized PAN‐PVP/ Fe3O4 composite films with different Fe3O4 contents were successfully prepared by carbonization under high temperature inert atmosphere to convert PAN and PVP into carbon materials. It was found that the PAN‐PVP/ Fe3O4 porous carbon film with 3 wt% Fe3O4 addition had a conductivity of 3.99 S·mm−1 at a thickness of 0.42 mm, and an average EMI SET of 78.9 dB, SEA of 64.8 dB, and SSEt of 1838 dB/(cm2·g−1) in the X‐band, which is a typical wave absorbing material and can meet commercial electromagnetic shielding requirements. This work provides new ideas and methods for the research and development of polymer‐based porous carbonized film as electromagnetic shielding materials.Highlights The carbon films with rich porous structure were prepared. Fe3O4 was successfully embedded into the carbon film. Carbon films have an efficient conducting network. Carbon film has excellent electromagnetic shielding performance. The main shielding mode of carbon film is absorption.

Effect of surface treatment of nickel-coated graphite on conductive rubber

Abstract In the blended conductive rubbers, good dispersion of conductive fillers and great interfacial bonding with the substrate are the keys to achieving excellent mechanical and electromagnetic shielding properties. It is found that compared with octyltriethoxysilane (A137), 3-methacryloxypropyl-trimethoxysilane (A174) and vinyltriethoxysilane (A151) with a double bond reduce the curing degree of the blends. The vinyl methyl silicone rubber/nickel-coated graphite (VMQ/NCG) composites modified by A137 shows poor tensile properties, while the composites modified by A174 shows inferior electrical properties. The presence of physical adsorption and chemical adsorption on the surface of NCG modified by A151, which effectively enhances the dispersibility of NCG and interfacial bonding strength with rubber, so that the material exhibits excellent comprehensive properties. When the content of A151 is 3% and modified by dry method, the tensile strength of VMQ/NCG composites can reach 1.6 MPa, the elongation at break can reach 162%, and the volume resistivity can reach 0.05 Ω·cm.

Ultrathin Ti3C2Tx MXene/Cellulose nanofiber composite film for enhanced mechanics & EMI shielding via freeze-thaw intercalation

Ultrathin Ti3C2Tx MXene/Cellulose nanofiber composite film for enhanced mechanics & EMI shielding via freeze-thaw intercalation

Vertically aligned liquid metal thermal pad with excellent electromagnetic shielding and ultra-high compressibility

Vertically aligned liquid metal thermal pad with excellent electromagnetic shielding and ultra-high compressibility

“Rigid-Flexible” structured polyimine/graphite felt composites with excellent fire Resistance, electromagnetic shielding and recyclability

“Rigid-Flexible” structured polyimine/graphite felt composites with excellent fire Resistance, electromagnetic shielding and recyclability

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

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

Tunable negative permittivity behavior and excellent electromagnetic shielding performance of pyrolytic carbon‐glass fiber felt/epoxy resin metacomposites

AbstractEffective and accurate adjustment of negative permittivity behavior is worthy of further investigation. Herein, pyrolytic carbon‐glass fiber felt/epoxy resin (PyC‐GFF/ER) metacomposites with tunable negative permittivity were prepared using an impregnation‐calcination method. The permittivity, electrical conductivity, and electromagnetic shielding performance of the polymer metacomposites were investigated. Due to the inherent three‐dimensional structural network of GFF, the PyC adhering to the surface of glass fiber easily formed a conductive network in the composites. As the PyC content increased in the ER composites, the conductivity mechanism changed from hopping conduction to metal‐like conduction. The ER composites with high PyC contents showed negative permittivity behavior and the epsilon‐near‐zero response owing to the low frequency plasma state of free electrons in the PyC‐conduction network. By controlling the PyC content, the negative permittivity behavior of ER composites could be effectively tuned. With the increase in PyC content, the values of negative permittivity increased, and the epsilon‐near‐zero frequency shifted to a higher frequency. Moreover, the ER composites with high PyC contents showed excellent electromagnetic shielding properties (29.4 dB) at X‐band. This work not only provided a feasible method to realize the tunable negative permittivity of polymer metacomposites, but also promoted its application in the microwave field.Highlights The pyrolytic carbon‐glass fiber felt/epoxy resin composites were fabricated. The negative permittivity was first reported in the PyC‐GFF/ER composites. Tunable negative permittivity could be well explained by Drude model. The polymer composites had excellent electromagnetic shielding property.

Nickel-plated cyanate Ester/melamine shape memory composites for stable electromagnetic shielding switch, infrared stealth, and flame retardancy

Nickel-plated cyanate Ester/melamine shape memory composites for stable electromagnetic shielding switch, infrared stealth, and flame retardancy

Zr4+ and Al3+ coordinated cross-linked conductive collagen fibers/solvent-free polyurethane foam with ultra-low reflective electromagnetic shielding properties

Zr4+ and Al3+ coordinated cross-linked conductive collagen fibers/solvent-free polyurethane foam with ultra-low reflective electromagnetic shielding properties

Cellulose nanofibers/liquid metal hydrogels with high tensile strength, environmental adaptability and electromagnetic shielding for temperature monitoring and strain sensors

Cellulose nanofibers/liquid metal hydrogels with high tensile strength, environmental adaptability and electromagnetic shielding for temperature monitoring and strain sensors

Room temperature self-healing and high gas barrier properties of elastomer composites incorporated with liquid metal

Room temperature self-healing and high gas barrier properties of elastomer composites incorporated with liquid metal

Influence of MXene Interlayer Spacing on the Interaction with Microwave Radiation

AbstractThe origin of MXene's excellent electromagnetic shielding performance is not fully understood. MXene films, despite being inhomogeneous at the nanometer scale, are often treated as if they are compared to bulk conductors. It is reasonable to wonder if the treatment of MXene as a homogeneous material remains valid at very small film thickness and if it depends on the interlayer spacing. The goal of the present work is to test if the homogeneous material model is applicable to nanometer‐thin Ti3C2Tx MXene films and, if so, to investigate how the model parameters may depend on variations in MXene interlayer spacings. MXene films containing flakes with interlayer spacing between 1.9 and 5.5 Å have been prepared using various intercalating agents. It is shown that modeling the films as being homogeneous agrees with experimental tests in the microwave frequency range. Microwave conductivity and dielectric constant parameters are estimated for the homogeneous film model by fitting measured results. The direct current (DC) conductivity matches the estimated microwave conductivity on the order of magnitude. A highly effective dielectric constant provides a good fit for the lower conductivity MXene films. Optical absorption agrees with the homogeneous material model of thin films as well.

Multifunctional Si3N4-skeleton-reinforced graphite flake composites with preferred orientation integrate excellent mechanical, thermophysical, and electromagnetic shielding properties

Multifunctional Si3N4-skeleton-reinforced graphite flake composites with preferred orientation integrate excellent mechanical, thermophysical, and electromagnetic shielding properties

Cellulose-reinforced foam-based phase change composites for multi-source driven energy storage and EMI shielding

Cellulose-reinforced foam-based phase change composites for multi-source driven energy storage and EMI shielding

Construction of porous graphene and network carbon nanotubes to develop high-performance and multifunctional carbon fiber composites

Construction of porous graphene and network carbon nanotubes to develop high-performance and multifunctional carbon fiber composites