scholarly journals Synthesis of Nickel Spinel Ferrites Nanoparticles Coated with Thermally Reduced Graphene Oxide for EMI Shielding in the Microwave, UV, and NIR Regions

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3316
Author(s):  
Asim Mansha ◽  
Khadija Zubair ◽  
Zulfiqar Ahmad Rehan ◽  
H. M. Fayzan Shakir ◽  
Talha Javed ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Electromagnetic Interference ◽  
Nanocomposite Film ◽  
Near Infrared ◽  
Initial Assessment ◽  
Emi Shielding ◽  
Casting Technique ◽  
Reduced Graphene ◽  
Co Precipitation

The co-precipitation and in situ modified Hummers’ method was used to synthesize Nickel Spinal Ferrites (NiFe) nanoparticles and NiFe coated with Thermally Reduced Graphene Oxide (TRGO) (NiFe-TRGO) nanoparticles, respectively. By using polyvinyl chloride (PVC), tetrahydrofuran (THF), and NiFe-TRGO, the nanocomposite film was synthesized using the solution casting technique with a thickness of 0.12–0.13 mm. Improved electromagnetic interference shielding efficiency was obtained in the 0.1–20 GHz frequency range. The initial assessment was done through XRD for the confirmation of the successful fabrication of nanoparticles and DC conductivity. The microstructure was analyzed with scanning electron microscopy. The EMI shielding was observed by incorporating a filler amount varying from 5 wt.% to 40 wt.% in three different frequency regions: microwave region (0.1 to 20 GHz), near-infrared (NIR) (700–2500 nm), and ultraviolet (UV) (200–400 nm). A maximum attenuation of 65 dB was observed with a 40% concentration of NiFe-TRGO in nanocomposite film.

scholarly journals Barium ferrite decorated reduced graphene oxide nanocomposite for effective electromagnetic interference shielding

2015 ◽  
Vol 17 (3) ◽  
pp. 1610-1618 ◽  
Author(s):  
Meenakshi Verma ◽  
Avanish Pratap Singh ◽  
Pradeep Sambyal ◽  
Bhanu Pratap Singh ◽  
S. K. Dhawan ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Electromagnetic Interference ◽  
Barium Ferrite ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Reduced Graphene

Barium ferrite decorated reduced graphene oxide nanocomposite has been synthesized for absorption dominated enhanced EMI shielding.

Synthesis of reduced graphene oxide paper for EMI shielding by a multi-step process

2020 ◽  
Vol 13 (05) ◽  
pp. 2051024
Author(s):  
Yangyang Lin ◽  
Genliang Hou ◽  
Song Bi ◽  
Xunjia Su ◽  
Hao Li
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Functional Groups ◽  
Electromagnetic Interference ◽  
Reduction Process ◽  
Emi Shielding ◽  
Hydroiodic Acid ◽  
X Band ◽  
Reduced Graphene ◽  
Graphene Oxide Paper

A multi-step reduction process was developed to produce reduced graphene oxide (rGO) paper for electromagnetic interference (EMI) shielding. First step reduction was achieved by hydroiodic acid to remove most of the oxygen-containing functional groups, and sodium borohydride was used in the second step reduction to reduce carbonyl group which is the most difficult functional group to remove. In the last step reduction, hydroiodic acid was used as reducing agent again to remove the remaining oxygen-containing functional groups. The results show that this method can greatly improve the conductivity and EMI shielding performance of rGO paper. The resulting rGO paper with a C/O ratio of 19.38 and a thickness of 9.1[Formula: see text][Formula: see text]m exhibited high conductivity of 1084[Formula: see text]S/cm and excellent average EMI shielding efficiency of 45.84[Formula: see text]dB in the X-band, better than that reduction by other chemical methods.

scholarly journals Polypropylene Nanocomposite Filled with Spinel Ferrite NiFe2O4 Nanoparticles and In-Situ Thermally-Reduced Graphene Oxide for Electromagnetic Interference Shielding Application

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 621 ◽  
Author(s):  
Yadav ◽  
Kuřitka ◽  
Vilčáková ◽  
Machovský ◽  
Škoda ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Electromagnetic Interference ◽  
Oxide Content ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Polypropylene Nanocomposites ◽  
Reduced Graphene ◽  
Nife2o4 Nanoparticles

Herein, we presented electromagnetic interference shielding characteristics of NiFe2O4 nanoparticles—in-situ thermally-reduced graphene oxide (RGO)—polypropylene nanocomposites with the variation of reduced graphene oxide content. The structural, morphological, magnetic, and electromagnetic parameters and mechanical characteristics of fabricated nanocomposites were investigated and studied in detail. The controllable composition of NiFe2O4-RGO-Polypropylene nanocomposites exhibited electromagnetic interference (EMI) shielding effectiveness (SE) with a value of 29.4 dB at a thickness of 2 mm. The enhanced EMI shielding properties of nanocomposites with the increase of RGO content could be assigned to enhanced attenuation ability, high conductivity, dipole and interfacial polarization, eddy current loss, and natural resonance. The fabricated lightweight NiFe2O4-RGO-Polypropylene nanocomposites have potential as a high performance electromagnetic interference shielding nanocomposite.

Sulfur-doped graphene laminates for EMI shielding applications

2015 ◽  
Vol 3 (38) ◽  
pp. 9802-9810 ◽  
Author(s):  
Faisal Shahzad ◽  
Pradip Kumar ◽  
Seunggun Yu ◽  
Seunghwan Lee ◽  
Yoon-Hyun Kim ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Electromagnetic Interference ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Laminated Structure ◽  
Significant Potential ◽  
Reduced Graphene ◽  
Doped Graphene ◽  
First Time

Herein, for the first time, we demonstrate that a laminated structure of sulfur-doped reduced graphene oxide (SrGO) provides significant potential for electromagnetic interference shielding applications.

scholarly journals Highly Efficient Wideband Microwave Absorbers Based on Zero-Valent Fe@γ-Fe2O3 and Fe/Co/Ni Carbon-Protected Alloy Nanoparticles Supported on Reduced Graphene Oxide

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1196 ◽  
Author(s):  
Francisco Mederos-Henry ◽  
Julien Mahin ◽  
Benoit P. Pichon ◽  
Marinela M. Dîrtu ◽  
Yann Garcia ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Electromagnetic Interference ◽  
Sol Gel ◽  
Absorption Efficiency ◽  
Superparamagnetic Nanoparticles ◽  
Complete Disappearance ◽  
Alloy Nanoparticles ◽  
Emi Shielding ◽  
Reduced Graphene

Electronic systems and telecommunication devices based on low-power microwaves, ranging from 2 to 40 GHz, have massively developed in the last decades. Their extensive use has contributed to the emergence of diverse electromagnetic interference (EMI) phenomena. Consequently, EMI shielding has become a ubiquitous necessity and, in certain countries, a legal requirement. Broadband absorption is considered the only convincing EMI shielding solution when the complete disappearance of the unwanted microwave is required. In this study, a new type of microwave absorber materials (MAMs) based on reduced graphene oxide (rGO) decorated with zero-valent Fe@γ-Fe2O3 and Fe/Co/Ni carbon-protected alloy nanoparticles (NPs) were synthesized using the Pechini sol-gel method. Synthetic parameters were varied to determine their influence on the deposited NPs size and spatial distribution. The deposited superparamagnetic nanoparticles were found to induce a ferromagnetic resonance (FMR) absorption process in all cases. Furthermore, a direct relationship between the nanocomposites’ natural FMR frequency and their composition-dependent saturation magnetization (Ms) was established. Finally, the microwave absorption efficiency (0.4 MHz to 20 GHz) of these new materials was found to range from 60% to 100%, depending on the nature of the metallic particles grafted onto rGO.

Cyanate Ester Resin Filled with Graphene Nanosheets and NiFe2O4–Reduced Graphene Oxide Nanohybrids for Efficient Electromagnetic Interference Shielding

NANO ◽  
2017 ◽  
Vol 12 (06) ◽  
pp. 1750066 ◽  
Author(s):  
Fang Ren ◽  
Yanfei Shi ◽  
Penggang Ren ◽  
Xiaohuan Si ◽  
Huan Wang
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Electromagnetic Interference ◽  
Graphene Nanosheets ◽  
Cyanate Ester ◽  
Electromagnetic Properties ◽  
Scanning Electron Micrographs ◽  
Emi Shielding ◽  
Blending Method ◽  
Reduced Graphene

An effective electromagnetic interference (EMI) shielding cyanate ester (CE) composite has been fabricated with a combination of graphene nanosheets (GNSs) and nickel ferrite (NiFe2O[Formula: see text] particles. NiFe2O4 particles were loaded on the reduced graphene oxide (RGO) to improve the dispersibility while the composites were synthesized via solution blending method. Scanning electron micrographs (SEM) showed good dispersion of GNSs and RGO–NiFe2O4 in CE. Electromagnetic properties and EMI shielding effectiveness (SE) of the nanocomposites were determined over X-bands (8.2–12.4[Formula: see text]GHz). It was observed that the EMI shielding performance of composites was improved by increasing the filler loading of composites and absorption was found to be the dominant shielding mechanism. The total EMI SE is almost reaching 50[Formula: see text]dB for samples with thicknesses of [Formula: see text]2.7[Formula: see text]mm, which suggests that the GNSs/RGO–NiFe2O4/CE could be good candidates for highly efficient EMI shielding materials in the whole X-band.

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

BioResources ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 814-824
Author(s):  
Zhibing Chen ◽  
Qinqin Zhang ◽  
Wanyao Meng ◽  
Zhenxing Wang ◽  
Xuewen Han ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Flexible Electronics ◽  
Electromagnetic Interference ◽  
Cellulose Nanofiber ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Filtration Method ◽  
Reduced Graphene ◽  
Composite Paper

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.

Constructing interconnected spherical hollow conductive networks in silver platelets/reduced graphene oxide foam/epoxy nanocomposites for superior electromagnetic interference shielding effectiveness

Nanoscale ◽  
2019 ◽  
Vol 11 (46) ◽  
pp. 22590-22598 ◽  
Author(s):  
Chaobo Liang ◽  
Ping Song ◽  
Hua Qiu ◽  
Yali Zhang ◽  
Xiangteng Ma ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Electromagnetic Interference ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Reduced Graphene ◽  
Electrical Conductivities ◽  
Electromagnetic Interference Shielding Effectiveness ◽  
Spherical Hollow

How to significantly increase electromagnetic interference (EMI) shielding performances by improving electrical conductivities is still a serious challenge.

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