Preparation and properties of graphene aerogel/cotton composite flexible fabric with electromagnetic interference (EMI) shielding function

2021 ◽  
pp. 152808372198927
Author(s):  
Peng Wang ◽  
Shuqiang Liu ◽  
Man Zhang ◽  
Gaihong Wu ◽  
Kaiwen Wang ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Waterborne Polyurethane ◽  
Development Trend ◽  
Electromagnetic Shielding ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Graphene Aerogel ◽  
Emi Shielding Effectiveness ◽  
Aerogel Composite ◽  
Electromagnetic Pollution

In order to alleviate the problems caused by electromagnetic pollution and simultaneously adapt to the future development trend of flexible wearable electronic equipment, it is high time to focus on the research of light weight, flexible and efficient electromagnetic interference (EMI) shielding material. A graphene aerogel composite EMI shielding composite fabric was prepared by combining graphene aerogel with fabric through the connection of waterborne polyurethane. The influence of aerogel amount on the EMI shielding function of fabric was discussed, and the waterborne polyurethane dosage on fabric mechanics and fabric style was also investigated. The result shows the composite fabric EMI shielding effectiveness reached 28 dB when the graphene aerogel amount was 25 mL (only 0.066 mL/cm2), which has satisfied the civilian requirements (20 dB). A good adhesion fastness between graphene and cotton fabric was obtained and the mechanical strength was also improved when the content of waterborne polyurethane was 20 mL. Graphene aerogel electromagnetic shielding composite fabric with good electromagnetic shielding performance and less consumption of nano carbon materials will have a good industrial application prospect.

scholarly journals A Novel Processing for CNT-Reinforced Mg-Matrix Laminated Composites to Enhance the Electromagnetic Shielding Property

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1030 ◽  
Author(s):  
Wanshun Zhang ◽  
Hongyang Zhao ◽  
Xiaodong Hu ◽  
Dongying Ju
Keyword(s):  
Electrophoretic Deposition ◽  
Electromagnetic Interference ◽  
Deposition Time ◽  
Laminated Composites ◽  
Electromagnetic Shielding ◽  
Matrix Composites ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Electromagnetic Plane Wave ◽  
Emi Shielding Effectiveness

The microstructure, electrical conductivity, and electromagnetic interference (EMI) shielding effectiveness (SE) of CNTs/Mg Matrix composites prepared by accumulative roll bonding (ARB) were systematically investigated to understand the effects of CNTs on the electromagnetic interference shielding effectiveness property of magnesium. A model based on the shielding of the electromagnetic plane wave was used to theoretically discuss the EMI shielding mechanisms of ARB-processed composites. The experimental results indicated that the methods were feasible to prepare laminated composites. The SE of the material increased gradually with the increase of electrophoretic deposition time. When the electrophoretic deposition time reached 8 min, the value of SE remained 87–95 dB in the frequency range of 8.2–12.4 GHz. The increase in SE was mainly attributed to the improvement in the reflection and multiple reflection losses of incident electromagnetic wave due to the increased amounts of CNTs and interfaces. The methods provided an efficient strategy to produce laminated metal matrix composites with high electromagnetic shielding properties.

scholarly journals Ultrathin Multilayer Textile Structure with Enhanced EMI Shielding and Air-Permeable Properties

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4176
Author(s):  
Shi Hu ◽  
Dan Wang ◽  
Aravin Prince Periyasamy ◽  
Dana Kremenakova ◽  
Jiri Militky ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Single Layer ◽  
Electromagnetic Shielding ◽  
Shielding Effect ◽  
Material Surface ◽  
Test Results ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Emi Shielding Effectiveness ◽  
Electromagnetic Shielding Effectiveness

A textile material’s electromagnetic interference (EMI) shielding effectiveness mainly depends on the material’s electrical conductivity and porosity. Enhancing the conductivity of the material surface can effectively improve the electromagnetic shielding effectiveness. However, the use of highly conductive materials increases production cost, and limits the enhancement of electromagnetic shielding effectiveness. This work aims to improve the EMI shielding effectiveness (EMSE) by using an ultrathin multilayer structure and the air-permeable textile MEFTEX. MEFTEX is a copper-coated non-woven ultrathin fabric. The single-layer MEFTEX SE test results show that the higher its mass per unit area (MEFTEX 30), the better its SE property between 56.14 dB and 62.53 dB in the frequency band 30 MHz–1.5 GHz. Through comparative testing of three groups samples, a higher electromagnetic shielding effect is obtained via multilayer structures due to the increase in thickness and decrease of volume electrical resistivity. Compared to a single layer, the EMI shielding effectiveness of five layers of MEFTEX increases by 44.27–83.8%. Due to its ultrathin and porous structure, and considering the balance from porosity and SE, MEFTEX 10 with three to four layers can still maintain air permeability from 2942 L/m2/s–3658 L/m2/s.

scholarly journals Ultrathin, Lightweight, and Flexible CNT Buckypaper Enhanced Using MXenes for Electromagnetic Interference Shielding

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Rongliang Yang ◽  
Xuchun Gui ◽  
Li Yao ◽  
Qingmei Hu ◽  
Leilei Yang ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
High Performance ◽  
Electronic Devices ◽  
Deposition Process ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Emi Shielding Effectiveness ◽  
X Band ◽  
Wearable Electronic Devices ◽  
Emi Se

AbstractLightweight, flexibility, and low thickness are urgent requirements for next-generation high-performance electromagnetic interference (EMI) shielding materials for catering to the demand for smart and wearable electronic devices. Although several efforts have focused on constructing porous and flexible conductive films or aerogels, few studies have achieved a balance in terms of density, thickness, flexibility, and EMI shielding effectiveness (SE). Herein, an ultrathin, lightweight, and flexible carbon nanotube (CNT) buckypaper enhanced using MXenes (Ti3C2Tx) for high-performance EMI shielding is synthesized through a facile electrophoretic deposition process. The obtained Ti3C2Tx@CNT hybrid buckypaper exhibits an outstanding EMI SE of 60.5 dB in the X-band at 100 μm. The hybrid buckypaper with an MXene content of 49.4 wt% exhibits an EMI SE of 50.4 dB in the X-band with a thickness of only 15 μm, which is 105% higher than that of pristine CNT buckypaper. Furthermore, an average specific SE value of 5.7 × 104 dB cm2 g−1 is exhibited in the 5-μm hybrid buckypaper. Thus, this assembly process proves promising for the construction of ultrathin, flexible, and high-performance EMI shielding films for application in electronic devices and wireless communications.

scholarly journals Electromagnetic Interference Shielding Performance Enhancement of Stretchable Transparent Conducting Silver Nanowire Networks with Graphene Encapsulation

2021 ◽  
Author(s):  
Siyi Yan ◽  
Peng Li ◽  
Zhongshi Ju ◽  
He Chen ◽  
Jiangang Ma
Keyword(s):  
Electromagnetic Interference ◽  
Performance Enhancement ◽  
Mechanical Stability ◽  
Silver Nanowire ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Dielectric Polarization ◽  
Emi Shielding Effectiveness ◽  
Graphene Films ◽  
Transparent Conducting

Abstract Silver nanowire (AgNW) networks are promising transparent conducting materials for electromagnetic interference (EMI) shielding and diverse optoelectronic devices. However, the poor contact between adjacent AgNWs leads to low electrical conductivity and weak mechanical stability of AgNW networks, which are limiting the practical application of these electronics. Here we report an efficient strategy to improve the overall performance of AgNW networks, in which the AgNW networks are sandwiched between two layers of graphene films. The graphene films improve the contact of overlapped AgNWs and bridge the discrete AgNWs, and thus increase the conductivity of graphene/AgNWs/graphene (GAG) films. Microwave permittivity measurements together with mechanism analyses reveal that the graphene films can enhance the EMI shielding effectiveness of AgNW networks through offering extra conduction loss, multiple dielectric polarization centers and multi-reflection processes. As a result, the GAG film with an average transmittance of 88% exhibits a sheet resistance lower than 15 Ω sq− 1 and an EMI shielding effectiveness of 31 dB (in the frequency range of 8.2‒12.4 GHz) after repeated stretching and release at a strain of 40%. Such a total performance is superior to that of most of as-reported transparent conductors. The GAG films therefore show application potential in the age of Internet of Things that electromagnetic radiation pollutions are everywhere.

Flexible, conductive, porous, fibrillar polymer–gold nanocomposites with enhanced electromagnetic interference shielding and mechanical properties

2017 ◽  
Vol 5 (5) ◽  
pp. 1095-1105 ◽  
Author(s):  
Jun Li ◽  
Hu Liu ◽  
Jiang Guo ◽  
Zhen Hu ◽  
Zhijiang Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Gold Nanoparticles ◽  
Self Assembly ◽  
Electromagnetic Interference ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Emi Shielding Effectiveness ◽  
Conductive Nanocomposites ◽  
Gold Nanocomposites

Flexible lightweight conductive nanocomposites prepared by self-assembly of gold nanoparticles on charged polymer nanofibers show enhanced EMI shielding effectiveness and mechanical properties.

EMI Shielding Properties of Polymer Blend with the Inclusion of Graphene Nano Platelets

2021 ◽  
Vol 875 ◽  
pp. 160-167
Author(s):  
Muhammad Fayzan Shakir ◽  
Asra Tariq
Keyword(s):  
Electromagnetic Interference ◽  
Coaxial Cable ◽  
Network Analyzer ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Electrically Conductive ◽  
Emi Shielding Effectiveness ◽  
Increasing Trend ◽  
Shielding Properties ◽  
Basic Prediction

Polymer nano composites based on poly vinyl chloride matrix were fabricated using polyaniline (PANI) and graphene nano platelets (GNP) as electrically conductive nano filler for the application of electromagnetic interference (EMI) shielding. DC conductivity was first evaluated by using cyclic voltammetry and found an increasing trend of electrical conductivity as PANI and GNP was added in PVC matrix that confirms the formation of electrically conductive network structure. Dielectric properties like dielectric constant, dielectric loss and AC conductivity were evaluated in frequency range of 100 Hz to 3 MHz that gives basic prediction for EMI shielding effectiveness. Vector Network Analyzer (VNA) was used to assess EMI shielding properties using coaxial cable method in 11GHz to 20GHz range and it was found that a maximum of 29 dB shielding was archived with the incorporation of 15 wt% of PANI in PVC. This value increased to 56 dB as 5 wt% GNP added in PVC/PANI 15 wt% blend. Interaction of matrix with filler, nature of filler and dispersion of filler in matrix are the key parameters for achieving high shielding effectiveness.

CNT@PDMS/NW composite materials with superior electromagnetic shielding

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Zi-Jing Zhou ◽  
Zhen-Xing Wang ◽  
Xiao-shuai Han ◽  
Jun-Wen Pu
Keyword(s):  
Electromagnetic Interference ◽  
Cellulose Nanofibers ◽  
Original Structure ◽  
Impregnation Method ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Band Frequency ◽  
Conductive Composites ◽  
Emi Shielding Effectiveness ◽  
Xrd Patterns

Abstract Lightweight materials with high electrical conductivity and hydrophobic mechanical properties are ideal materials for electromagnetic interference (EMI) shielding. Herein, the conductive composites with great EMI shielding effectiveness (SE) were successfully obtained by introducing multi-walled carbon nanotube (CNT) and polydimethylsiloxane (PDMS) based on the original structure of natural wood (NW). CNT@PDMS/NW composites were prepared via vacuum-pulse impregnation method and characterized by Fourier transform infrared (FTIR), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) patterns, hydrophobicity analysis, and EMI shielding performance. As demonstrated, CNT nanosheets were successfully inserted into wood matrices, and hydrogen bonding between CNT nanosheets and cellulose nanofibers induced the fabrication of CNT@PDMS/NW composites. CNT@PDMS/NW composites exhibited excellent EMI SE values of 25.2 dB at the X-band frequency.

Freestanding Fe3O4 / Ti3C2Tx MXene / polyurethane composite film with efficient electromagnetic shielding and ultra-stretchable performance

2022 ◽  
Author(s):  
Yongqin Hu ◽  
Chen Hou ◽  
Yuxia Shi ◽  
Jiamei Wu ◽  
Da Yang ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Tensile Elongation ◽  
Energy Conversion Efficiency ◽  
High Energy ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Emi Shielding Effectiveness ◽  
Polyurethane Composite ◽  
Human Reproductive ◽  
Interfacial Scattering

Abstract Electromagnetic pollution seriously affects the human reproductive system, cardiovascular system, people’s visual system, and so on. A novel versatile stretchable and biocompatible electromagnetic interference (EMI) shielding film has been developed, which could effectively attenuate electromagnetic radiation. The EMI shielding film was fabricated with a convenient solution casting and steam annealing with 2D MXene, iron oxide nanoparticles, and soluble polyurethane. The EMI shielding effectiveness is about 30.63 dB at 8.2 GHz, based on its discretized interfacial scattering and high energy conversion efficiency. Meanwhile, the excellent tensile elongation is 30.5%, because of the sliding migration and gradient structure of the nanomaterials doped in a polymer matrix. In addition, the film also demonstrated wonderful biocompatibility and did not cause erythema and discomfort even after being attached to the arm skin over 12 hours, which shows the great potential for attenuation of electromagnetic irradiation and protection of human health.

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