Excellent Electromagnetic Shielding Effectiveness Research Articles

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

Flexible electronic devices require stretchable packaging materials that provide a hermetic seal. However, conventional soft materials often exhibit strong gas permeability, making it difficult to achieve stable operation, which requires films with high deformability, self-healing capability, and gas barrier functionality. In this study, a layer by layer (LBL) method was employed to uniformly coat a controllable thickness of liquid metal (LM) onto a designed and synthesized self-healing thermoplastic polyurethane (TPU) film, successfully developing a stretchable gas barrier film (TPU/LM) with high gas barrier properties. The designed polyurethane film significantly enhanced the adhesion of the liquid metal, effectively preventing leakage. The experimental results show that the water vapor transmission rate (WVTR) of the TPU/LM composite film with a thickness of 40 μm is 4.04g/(m2·day). Compared to the film without LM, the gas barrier performance has been improved by approximately 16 times. Additionally, there is a significant enhancement in nitrogen (N2) barrier, with a permeation rate reaching 4.0*10−17 cm3 cm/(cm2·s·Pa), effectively blocking the N2 permeation. This demonstrates the universality of the TPU/LM in gas barrier applications. Furthermore, the TPU/LM film also demonstrated excellent electromagnetic shielding effectiveness. The self-healing capability of the stretchable gas barrier film allows it to recover its initial gas barrier performance after mechanical damage. Humidity-sensitive resistors encapsulated with TPU/LM exhibited stable operation in both air and 90 % humidity environments, confirming the superior barrier properties of the TPU/LM. Generally, the developed TPU/LM is suitable for packaging applications in the next generation of flexible electronic devices.

Multifunctional wood-derived cellulose/Ti3C2Tx composite films enhanced by densification strategy for electromagnetic shielding, Joule/solar heating, and thermal camouflage

In the era of increasing reliance on electronic devices, the development of flexible smart composite films that offer multifunctional capabilities such as electromagnetic shielding, sensing, infrared stealth, and autonomous heating is becoming increasingly significant. In this study, we fabricated polydopamine-modified cellulose scaffold/MXene composite films (PCM) using a densification strategy, resulting in films with a thickness of only 33 μm, outstanding tensile strength of 235.28 MPa, and excellent electromagnetic shielding effectiveness of 44.6 dB. The PCM also demonstrates remarkable electrothermal performance, reaching temperatures of up to 610 °C at 5 V, and exhibits excellent photo-thermal conversion performance, along with good cycling stability and tunability. Additionally, the PCM’s low infrared emissivity provides it with exceptional infrared stealth capabilities, effectively concealing a high surface temperature ranging from 250 °C to 25 °C. The PCM’s ability to detect human body movement and light-driven actuation for bionic motions underscores its flexibility and utility as a sensor. Therefore, this efficient and versatile approach provides a promising method for synthesizing multifunctional MXene-based composite films, achieving satisfactory mechanical properties, high electromagnetic interference shielding, and effective thermal management for wearable smart devices and military applications.

Enhanced electromagnetic shielding with ultrathin VGNs-Metal hybrid structures

Designing and preparing lightweight electromagnetic shielding materials at the micron level is crucial for aerospace and military applications. Vertical graphene nanowalls (VGNs) offer high efficiency for electromagnetic shielding due to attributes such as high carrier mobility, porosity, and low density. This study presents the preparation of ultra-thin VGNs/metal stacked films via plasma-enhanced chemical vapor deposition (PECVD) for VGNs, and combined electron beam evaporation (EBE) with cyclic PECVD for metal layers. The PECVD technique ensures homogeneity and controllable thickness of the VGNs. The experimental results demonstrate that the interface between the VGNs and the metal layer exhibits good interfacial contact, resulting in high carrier mobility. Furthermore, incorporating a metal layer with a thickness ratio of 10 % significantly enhances conductivity by an order of magnitude. The hybrid structures exhibit remarkable electromagnetic shielding effectiveness per unit thickness (∼5300 dB mm−1) evaluated in the X-band range (8–12 GHz). Stacked films as thin as 0.01 mm achieve up to 53.4 dB of electromagnetic shielding. Finite element simulations indicate that the presence of opposing electric fields at the graphene-metal interface contributes to higher ohmic loss. The coupling effect at the interface significantly contributes to the material's excellent electromagnetic shielding effectiveness.

Multi-Functional and Flexible Nano-Silver@MXene Heterostructure-Decorated Graphite Felt for Wearable Thermal Therapy.

Wearable heaters with multifunctional performances are urgently required for the future personal health management. However, it is still challengeable to fabricate multifunctional wearable heaters simultaneously with flexibility, air-permeability, Joule heating performance, electromagnetic shielding property, and anti-bacterial ability. Herein, silver nanoparticles (AgNPs)@MXene heterostructure-decorated graphite felts are fabricated by introducing MXene nanosheets onto the graphite felts via a simple dip-coating method and followed by a facile in situ growth approach to grow AgNPs on MXene layers. The obtained AgNPs@MXene heterostructure decorated graphite felts not only maintain the intrinsic flexibility, air-permeability and comfort characteristics of the matrixes, but also present excellent Joule heating performance including wide temperature range (30-128 °C), safe operating conditions (0.9-2.7V), and rapid thermal response (reaching 128 °C within 100 s at 2.7V). Besides, the multifunctional graphite felts exhibit excellent electromagnetic shielding effectiveness (53dB) and outstanding anti-bacterial performances (>95% anti-bacterial rate toward Bacillus subtilis, Escherichia coli and Staphy-lococcus aureus). This work sheds light on a novel avenue to fabricate multifunctional wearable heaters for personal healthcare and personal thermal management.

Porous polypyrrole Nanotube-Based Organohydrogels: Versatile materials for robust electromagnetic interference shielding in harsh environments

Wearable and multi-functional electromagnetic interference (EMI) shielding materials are an inevitable trend in order to cope with increasingly complex practical applications. In the present work, polypyrrole nanotube (PNT)-based organohydrogels (POGs) with excellent electromagnetic shielding effectiveness (SE) were synthesized through a facile sol–gel strategy. The obtained POGs offer distinct shielding performance, anti-drying, anti-freezing, plasticity and recyclable ability. The POG with a 20 wt% PNTs filling exhibits a SET of 63.6 dB in the X-band at a thickness of 2.0 mm. After being placed at ambient temperature for 30 days and − 40 ℃ for 4 h, its SE values still retained at 50.3 dB and 59.3 dB, respectively. Moreover, after being immersed in the solvents, the POG (left in the air for 30 days) can recover flexibility and 92 % of its original EMI shielding performance. Importantly, crushing the fully dried organohydrogels into the powder and placing it again in the solvents fully restores its flexibility and EMI shielding properties. The glorious shielding and mechanical characteristics can be ascribed to the superior conductivity of PNTs and the highly crosslinked stable network of PVA, as well as the further enhancement of the crosslinked network by cellulose nanofibers. In addition, ​sensors based on POGs can effectively detect human movement and strain deformations. This work thus provides fresh insight into exploring the sustainability of flexible and wearable EMI shielding materials for handling extreme environments.

Light Weight, Flexible and Ultrathin PTFE@Ag and Ni@PVDF Composite Film for High-Efficient Electromagnetic Interference Shielding.

Dopamine was used to modify polytetrafluoroethylene (PTFE) in order to obtain functional polydopamine (PDA) surface-modified PTFE microporous film (PTFE@PDA). Ag was deposited on the surface of PTFE@PDA using electroless plating in order to obtain Ag-wrapped PTFE@PDA film (PTFE@Ag). A liquid-phase chemical reduction method was employed to prepare nickel nanochains. A Ni@PVDF cast film was obtained by mechanically blended nickel nanochains and polyimide (PVDF). The above two films were hot pressed to give a flexible, ultra-thin, and highly effective electromagnetic shielding composite film with a "3+2" layered structure. IR, XRD, and TEM results showed the PTFE@PDA film surface was coated by a tight plating layer of Ag particles with a particle size of 100~200 nm. PTFE@Ag+Ni@PVDF composite film exhibited excellent electromagnetic shielding effectiveness, with the conductivity of 7507.5 S/cm and the shielding effectiveness of 69.03 dB in the X-band range. After a 2000-cycle bending, this value still remained at 51.90 dB. Furthermore, the composite film presented excellent tensile strength of 62.1 MPa. It has great potential for applications in flexible and wearable intelligent devices.

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.

Multifunctional composite polyvinyl alcohol films prepared with economic conductive carbon black and MXene microcapsuled APP

Multifunctional flexible electrothermal film has the advantages of high heating efficiency, good heat dissipation conditions, high surface power density, flame retardant and so on, which is widely used in construction, medical, agriculture, military, household products and other fields. In this work, a new type of economical, environmentally friendly, fire-safe electrothermal and electromagnetic (EMI) shielding composite film with PVA as the binder was prepared by introducing MXene-microcapsuled ammonium polyphosphate (MAPP) and conductive carbon black (CCB). After the addition of MAPP as a synergist, the conductivity of the PVA/CCB/MAPP films was increased by 66.5%. In addition, it shows excellent EMI shielding effectiveness (47.1 dB, 0.4 mm thickness). Furthermore, the PVA/CCB/MAPP thin film can reach 100 °C at an applied voltage of 12 V. These results also show good cycling and long-term electrothermal performance. In the combustion performance test, compared with PVA-0, the PVA/CCB/MAPP film had an 86.6% lower pHRR, and the THR was decreased by 59.9%. The surface temperatures of the wood sticks and FPUF reached 79.9 °C and 62.1 °C, respectively, showing excellent electrothermal effects. The PVA/CCB/MAPP film can also completely inhibit the combustion of FPUF. In short, the study offers a novel method to gain eco-friendly, fire safety and EMI shielding electrothermal films that can be coated on different substrates.

Effects of Y2O3 on the microstructure evolution and electromagnetic interference shielding mechanism of soft magnetic FeCoSiMoNiBCu alloys by laser cladding

Laser cladding is one of the new techniques for additive manufacturing of metal alloy-based electromagnetic shielding materials. However, it is generally difficult to prepare alloys with ideal printability, soft magnetism and electromagnetic interference (EMI) shielding effectiveness (SE) using this technique. To improve the electromagnetic shielding performance of laser cladded Fe-Co based soft magnetic alloys, a new FeCoSiMoNiBCu alloy was prepared by laser multilayer cladding using metal powders added with different content of Y 2 O 3 . The results show that the FeCoSiMoNiBCu alloys prepared under optimized laser processing parameters exhibit excellent soft magnetism and electromagnetic shielding properties. The microstructure of the prepared alloys is mainly composed of α (bcc) phase, Fe 2 B, YFe 10 Mo 2 and B 6 Co 21 Mo 2 phases. The Y 2 O 3 powder has played significant effects on the soft magnetism and electromagnetic shielding properties of the alloys. When added with 1.5 wt% Y 2 O 3 , the alloy samples exhibit the highest saturation magnetization (186.2 emu/g) together with a superior EMI shielding effectiveness of 95 dB at 23.5 GHz, which is a 25–58% improvement compared the alloy without adding Y 2 O 3 . The mechanisms for the improved EMI shielding performance of the laser cladded FeCoSiMoNiBCu alloys depend on a synergistic effect of enhanced dielectric loss and ohmic loss; specifically, the α-Fe mainly promotes the dielectric loss, while the ohmic loss is enhanced by a “fish-bone” shaped phase composed of α (bcc) phase, Fe 2 B, YFe 10 Mo 2 and B 6 Co 21 Mo 2 . This study provides a new theoretical and technical guidance for the development of high-performance EMI shielding alloys using laser cladding technique. • A new FeCoSiMoNiBCu alloy with excellent electromagnetic shielding effectiveness was successfully prepared by laser cladding. • The microstructure evolution mechanism of Y 2 O 3 promoted laser cladding FeCoSiMoNiBCu alloys was clarified. • The influence of the type, size and proportion of in-situ magnetic phases on the FeCoSiMoNiBCu alloy’s electromagnetic shielding interference model was established by the experiments and first-principles calculations. • The electromagnetic shielding interference effectiveness of the laser cladding new FeCoSiMoNiBCu alloy was improved about 25–58%.

Fabrication of durable and conductive cotton fabric using silver nanoparticles and PEDOT:PSS through mist polymerization

Conductive cotton fabrics are widely used in electromagnetic shields and soft sensors because of their excellent softness and comfort. Generally, conductive cotton fabrics are prepared by depositing an inorganic conductive coating or an organic conductive polymer coating on them. However, due to the complex structure of cotton fabrics, these conductive coatings easily fall off and fracture under external forces, resulting in a sharp decline in the conductive properties of the finished fabrics. In the present work, L-cysteine was used as a binder to immobilize Ag NPs on cotton fabric. Ag NPs were covered by PEDOT:PSS to prevent them from falling off and cracking. As a result, the surface resistance of finished fabric was arrived at 8.7 Ω/sq. The finished fabric also exhibited excellent electromagnetic shielding effectiveness, with an electromagnetic shielding reached at 27.1 dB. Moreover, the composite coating significantly improved the durability of electrical conductivity and electromagnetic shielding properties of the finished fabric. In addition, mist polymerization was used to retain the inherent properties of the cotton fabric. We believe that the proposed method provides a new direction for the preparation of conductive cotton fabrics with a high stability.

Waste cotton Fabric/MXene composite aerogel with heat generation and insulation for efficient electromagnetic interference shielding

Electromagnetic interference (EMI) shielding materials have become more and more indispensable due to serious electromagnetic-radiation pollution. Herein, waste cotton cellulose aerogels were prepared by dissolving waste cotton fabrics (WCF) in NaOH/urea aqueous solution, and MXene nanosheets were subsequently deposited on the cellulose aerogels by a facile dip coating method to obtain WCF/MXene composite aerogels. The WCF/MXene composite aerogels with highly porous network structure show remarkable electrical conductivity (8.2 Ω/sq of surface resistance), high EMI shielding effectiveness (EMI SE) in the range of 2–18 GHz (39.3–48.1 dB). The WCF/MXene aerogel possesses high SSE and SSE/t of 677.94–829.74 dB cm3 g−1 and 3512.62–4299.17 dB cm2 g−1, respectively (2–18 GHz). In addition, the heating temperature of WCF/MXene composite aerogels reaches 199 °C when 3 V positive voltage is applied on them. The WCF/MXene composite aerogels possess excellent electromagnetic shielding effectiveness, heat generation property and insulation, which can be potentially used as multifunctional materials for EMI shielding, electrical-heating and high temperature protection.

Effects of Impedance and Dielectric Loss on the Electromagnetic Shielding Performance of an Ultrathin Carbon Nanotube Buckypaper‐Reinforced Silicon Carbide Nanocomposite

An ultrathin carbon nanotube buckypaper‐reinforced silicon carbide (CNT/SiC) nanocomposite with a thickness of 500 μm and density of 1.78 g cm−3 is prepared by combining a CNT buckypaper preform and an in situ‐synthesized SiC matrix. A uniform CNT distribution and a high CNT content (≈35 vol%) are achieved in the nanocomposite. The SiC matrix is composed mostly of nearly spherical nanograins and submicrometer grains. No residual Si is found. The imaginary permittivity and loss tangent of the nanocomposite throughout the X‐band are 96–257 and 0.44–7.03, respectively. The normalized input impedance is 0.0012–0.0174 over the X‐band. The nanocomposite has an average total shielding effectiveness (SE) of 30 dB throughout the X‐band. The nanocomposite has a reflection coefficient of 0.9651–0.9915, an absorption coefficient of 0.0077–0.0338, and a transmission coefficient of no more than 0.0012 throughout the X‐band, indicating excellent electromagnetic SE. The nanocomposite is well suited for shielding applications, and the SE due to internal absorption (SEA) depends mostly on the impedance matching condition rather than the dielectric loss capacity. The variation with frequency of SEA is not consistent with that of the imaginary permittivity or loss tangent but approximately consistent with that of the normalized input impedance.

Synergism between lignin, functionalized carbon nanotubes and Fe3O4 nanoparticles for electromagnetic shielding effectiveness of tough lignin-based polyurethane

In this work, a kind of novel flexible lignin-based electromagnetic shielding polyurethane (FeCLPU) with excellent properties was prepared and studied. Lignin was applied as an reinforcement with modified carbon nanotubes (CNT) and aminated ferroferric oxide nanoparticles (Fe3O4) in polyurethane to improve electromagnetic shielding properties. The KH550-modified Fe3O4 was mixed with lignin, polyethylene glycol (PEG), hexamethylene diisocyanate (HDI) and modifiedCNT to in situ synthesize FeCLPU. When the concentrations of both Fe3O4 and CNT were 10% and the lignin content was 15%, the maximum EMI SE reached 37.5 dB. This excellent electromagnetic shielding effectiveness was attributed to the synergistic effects between the Fe3O4, CNT and lignin. The tensile strength attained 7.25 MPa. Thus, the FeCLPU with uniformly dopped Fe3O4 and CNT was expected to be promising in a wide array of applications in civilian fields, due to its excellent overall performance, low cost and eco-friendliness.

A cauliflower-shaped nickel @ porous calcium silicate core-shell composite: Preparation and enhanced electromagnetic shielding performance

Modifying magnetic metals on the surface of inorganic porous materials can not only impart conductive and magnetic ability to inorganic insulating materials, but also make full use of the rich porous structure of porous materials to absorb and consume electromagnetic energy when electromagnetic waves are incident. In this work, a cauliflower-shaped nickel-plated porous calcium silicate (Ni@PCS) functional composite with core-shell structure was successfully fabricated via electroless plating. The electromagnetic shielding performance of the prepared Ni@PCS was investigated and the corresponding electromagnetic shielding mechanism was discussed. Results indicate that the prepared Ni@PCS achieves excellent electromagnetic shielding effectiveness of 58.1 dB at X band with only 0.9 mm of sample thickness. The synergistic effect of multiple energy dissipation is the main electromagnetic shielding mechanism of this core-shell composite. The nickel shell with excellent electrical and magnetic conductivity is responsible for most of the reflection loss and magnetic loss; the interface between the PCS core and the nickel shell produces interfacial polarization loss, while the cauliflower-shaped porous structure provides the internal multiple reflection loss. The results also illustrate that coating magnetic metals on the surface of inorganic porous materials is an effective strategy to prepare high-performance electromagnetic shielding composite materials.

Fe ionic induced strong bioinspired Fe3O4@graphene aerogel with excellent electromagnetic shielding effectiveness

The graphene oxides would be reduced by dopamine self-polymerization to self-assembly graphene hydrogel and the graphene building blocks were covered with polydopamine. In order to obtain stronger aerogel with excellent electromagnetic interference shielding effectiveness (EMISE), bioinspired by mussel byssus, Fe3+/Fe2+ were introduced into the preparation process. Fe ionic endowed the aerogel with a remarkable combination of high hardness and extensibility by hydroxyl/amine-Fe3+ chelation cross-links. When PH = 10, the Fe3O4 in-situ coated on the aerogel surface, which also enhanced the mechanical and magnetic loss properties of aerogel. After pyrolysis under 800 °C, Fe-N coordination complex and stable Fe3O4 still exhibited mechanical strengthening effect. As for EMISE, Fe/N doping and flower-like Fe3O4 were also beneficial for dielectric and magnetic polarity, thus improved its related properties. Compared with that of pristine graphene aerogel, the compressive strength of 4 mg/mL Fe3+ induced Fe3O4@graphene aerogel under 50% strain increased by 22.9% and high compressive recoverability under 90% strain was observed. The EMISE was also improved over wide band range of 2–18 GHz. For high frequency, SE value of samples with 2 mm thickness was as high as 41 dB. Furthermore, owing to annealing process, it could be inferred that it would be applied in high temperature filed.

Multifunctional Stretchable Conductive Woven Fabric Containing Metal Wire with Durable Structural Stability and Electromagnetic Shielding in the X-Band.

Elastomeric, conductive composite yarns have recently received attention around the opportunity for them to offer special protective fields. A straightforward approach for fabricating tri-component elastic-conductive composite yarns (t-ECCYs) containing stainless steel wire (SSW) was proposed previously. This work mainly focuses on the electromagnetic shielding effectiveness (EMSE) of weft-stretchable woven fabric containing t-ECCY over the X-band under different testing conditions, e.g., single step-by-step elongation, cyclic stretch and lamination events. Results showed that a woven cotton fabric with weft yarn of t-ECCY not only exhibited superior weft stretch-ability to a higher elongation (>40%) compared with a pure cotton control but also had an acceptable 15-cyclic stability with 80% shape recovery retention. The t-ECCY weft fabric was effective in shielding electromagnetic radiation, and its EMSE was also enhanced at elevated elongations during stretch at parallel polarization of EM waves. There was also no decay in EMSE before and after the t-ECCY fabric was subject to 15 stretch cycles at extension of 20%. In addition, a 90° by 90° cross lamination of t-ECCY fabric remarkably improved the EMSE compared to a 0°/90° one. The scalable fabrication strategy and excellent EMSE seen in t-ECCY-incorporated fabrics represent a significant step forward in protective fields.

Ni@nylon mesh/PP composites with a novel tree-ring structure for enhancing electromagnetic shielding

Two different composites one with a novel tree-ring structure and the other with a multi-layer structure were fabricated based on polypropylene (PP) film and Ni@nylon mesh by using the hot compressive molding. The Ni@nylon mesh prepared by electroless Ni plating generated continuously conductive networks for the composites to possess excellent electromagnetic shielding effectiveness (SE) along with the improvements of thermal conductivities. The maximum SE value of the composites with tree-ring structure achieved 50.6 dB, which was greater than that (25.8 dB) of the conventional multi-layer composites. There was not much difference in thermal conductivity (0.53–0.55 W/m·K) for both two composites with 3.07 vol% Ni, while they were still about 1.2 times higher than that of composites without Ni inclusion. Moreover, the compressive strength (48.8 MPa) of composite with tree-ring structure was higher than that (45.7 MPa) of multi-layer composite at the same Ni content (3.07 vol%).

Light-weight and highly flexible TaC modified PyC fiber fabrics derived from cotton fiber textile with excellent electromagnetic shielding effectiveness

For the first time, tantalum carbide (TaC) nanoparticles modified pyrolytic carbon fiber (TaC/PyC)f fabrics were elaborately designed and fabricated through in-situ formation of TaC nanophase on the surface of PyCf fabrics derived from pyrolysis of cotton fiber clothes. The introduction of highly electrically conductive TaC nanophase significantly improved the electrical conductivity and interaction capability of (TaC/PyC)f fabrics with electromagnetic waves in terms of reflection and absorption, which leads to a significant increase in the total shielding effectiveness (SET). With a thickness of ~260 μm, the best SET of the resultant (TaC/PyC)f fabrics can reach 75.0 dB compared to 24.4 dB of the PyCf fabrics with otherwise identical conditions. Through employing both the advantages of TaC and Cf, flexible, thin and light-weight (TaC/PyC)f fabrics possessing excellent SE were obtained.

Nickel-reduced graphene oxide-cellulose nanofiber composite papers for electromagnetic interference shielding

With the widespread use of electronic communication devices, ultra-thin, flexible, and high-performance electromagnetic interference (EMI) shielding materials are widely used to prevent radiation pollution. Moreover, graphene-reinforced polymer-based nanocomposites have received increasing attention in the field of EMI shielding because of their excellent electrical properties. In this work, ultrathin and flexible nickel/reduced graphene oxide/cellulose nanofiber (Ni/RGO/CNFs) composite paper was fabricated using a step-by-step vacuum-assisted filtration method. The prepared composite paper with Ni/RGO to CNF ratio of 3:1 and a thickness of 105 µm attained the electrical conductivity of 1664 S/m and 22.6 dB of excellent electromagnetic shielding effectiveness (SE). In addition, the composite paper (2:1) exhibited great mechanical properties, leading to a high tensile strength of 78.4 MPa, 10.3% fracture strain, and no obvious fractures or cracks when the composite paper was folded. Therefore, the Ni/RGO/CNFs composite paper prepared in this study is an effective lightweight shielding material, especially in flexible electronics and wearable devices.

Development of Poly (vinylidene fluoride) and Polyaniline blend with high dielectric permittivity, excellent electromagnetic shielding effectiveness and Ultra low optical energy band gap: Effect of ionic liquid and temperature

Electrically conductive polymer blends have attracted profound attention as dielectric materials. However, achieving isotropic behavior, electrical stability and low current leakage is still challenging. Here we have synthesized a conductive polymer blend of Polyaniline (PANI) and Poly (vinylidene fluoride) (PVDF) exhibiting relatively high dielectric permittivity (εʹ) together with low band gap. Ionic liquid (IL) has been incorporated and the effect of IL in the dielectric properties are explored. The interfacial adhesion, morphology and the dielectric polarization of the blends are investigated. The electromagnetic shielding effectiveness (EMISE) of the conductive blends is studied in X-band frequency range. The electrical stability and decrease in current loss of the blends has been analyzed through I–V characteristics. The findings reveal that with increase in PANI loading in the temperature range of 25–100 °C and IL incorporation results in excellent dielectric properties for charge storage applications. The high efficiency of absorption and low transmission of electromagnetic radiation by the conductive blends is the main reason for excellent EMISE possessed by the systems which can be used for shielding applications in electronics. The increase in electrical stability and decrease in current leakage ability appear in the form of narrow band gap.