Researching on X-Band Electromagnetic Interference Shielding Efficiency of MWCNTs Buckypapers Inserted with Mn Nanopowder

NANO ◽  
2018 ◽  
Vol 13 (06) ◽  
pp. 1850061 ◽  
Author(s):  
Shaowei Lu ◽  
Yaoyao Bai ◽  
Jijie Wang ◽  
Chenxu Zhao ◽  
Wei Li ◽  
...  

Ultrathin multi-walled carbon nanotubes (MWCNTs) buckypapers inserted with Mn nanopowder were fabricated via vacuum filtration method, at a lower manufacturing cost and easier operation. The buckypapers were characterized structurally using scanning electron microscopy, energy-dispersive spectrometer and X-ray diffraction. Electromagnetic interference (EMI) shielding effectiveness (SE) of MWCNTs buckypapers inserted with Mn nanopowder (0–30[Formula: see text]wt.%) were tested in X-band (8.2–12.4[Formula: see text]GHz). When the blended Mn nanopowder content is 20[Formula: see text]wt.%, the buckypaper exhibits much higher EMI SE of average value up to 42[Formula: see text]dB with the thickness of only 0.11[Formula: see text]mm. Further, this buckypaper is flexible and lightweight, and can be integrated with resin matrix composites. Thus, the results and techniques promise a simple and effective approach to achieve lightweight and ultrathin composite films for a wide application prospect in the field of EMI shielding and microwave absorption.

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Rongliang Yang ◽  
Xuchun Gui ◽  
Li Yao ◽  
Qingmei Hu ◽  
Leilei Yang ◽  
...  

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.


NANO ◽  
2019 ◽  
Vol 14 (06) ◽  
pp. 1950075 ◽  
Author(s):  
Shaowei Lu ◽  
Yaoyao Bai ◽  
Jijie Wang ◽  
Dandan Chen ◽  
Keming Ma ◽  
...  

As the portable device hardware has been increasing at a noticeable rate, ultrathin flexible materials with the combination of high thermal conductivity and excellent electromagnetic interference (EMI) shielding performance are urgently needed. Here, we fabricated ethylene propylene diene monomer rubber with different loading graphene nanoplatelets (GnPs/EPDM) by a cost-efficient approach, which combines mixing, ultrasonication and compression. Further investigation demonstrates that the 8[Formula: see text]wt.% GnPs/EPDM with only 0.3[Formula: see text]mm in thickness shows excellent electrical conductivity (28.3[Formula: see text]S/m), thermal conductivity (0.79[Formula: see text]W/m[Formula: see text]K) and good mechanical properties. Besides, the 8[Formula: see text]wt.% GnPs/EPDM exhibits an EMI shielding effectiveness (SE) up to 33[Formula: see text]dB in the X-band (8.2–12.4[Formula: see text]GHz) and 35[Formula: see text]dB in the Ku-band (12.4–18[Formula: see text]GHz), superior to most of the reported rubber matrix. Additionally, the GnPs/EPDM shows excellent flexibility and stability with 95% and 94% retention of EMI SE even after repeated bending for 5000 times and corrosion (under 5% NaCl environment) for a week. Our flexible EMI shielding material will benefit the fast-growing next-generation commercial portable flexible electrons.


Nanoscale ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 3308-3316 ◽  
Author(s):  
Caichao Wan ◽  
Yue Jiao ◽  
Xianjun Li ◽  
Wenyan Tian ◽  
Jian Li ◽  
...  

A multi-dimensional and level-by-level assembly strategy is developed to construct free-standing and sandwich-type nanoheterostructures achieving an outstanding EMI shielding effectiveness of ∼50.6 dB in the X-band.


2016 ◽  
Vol 4 (2) ◽  
pp. 371-375 ◽  
Author(s):  
Qing Yuchang ◽  
Wen Qinlong ◽  
Luo Fa ◽  
Zhou Wancheng ◽  
Zhu Dongmei

Graphene nanosheets filled BaTiO3 ceramics with high-performance EMI shielding effectiveness, greater than 40 dB in the X-band at 1.5 mm thickness, were prepared via pressureless sintering.


2015 ◽  
Vol 3 (4) ◽  
pp. 820-827 ◽  
Author(s):  
Hilal Ahmad Reshi ◽  
Avanish P. Singh ◽  
Shreeja Pillai ◽  
Rama Shankar Yadav ◽  
S. K. Dhawan ◽  
...  

EMI shielding effectiveness values of up to 19 dB are observed in LSMO nanomaterials.


2012 ◽  
Vol 488-489 ◽  
pp. 557-561 ◽  
Author(s):  
Muhammad Faisal ◽  
Syed Khasim

Insitu polymerization of aniline was carried out in the presence of stannous oxide (SnO) to synthesize Polyaniline (PAni)/SnO composites by chemical oxidation method. The surface morphology of the composites were studied by scanning electron microscopy (SEM).The electromagnetic interference (EMI) shielding properties of the composites were investigated for different wt % of SnO (10,20,30,40 and 50 wt%) in PAni. The EMI measurements were carried out in the frequency range from 8.2 to 12.4 GHz (X-band), which is relevant for practical applications. EMI shielding effectiveness (EMI SE), microwave absorption and reflection, the influence of SnO concentration in PAni on EMI SE of the composites are reported. The composites exhibit EMI SE value of -18 to -23 dB. The absorption dominated EMI SE of these composites indicates the potential applications of these materials for microwave attenuation in the X-band.


2021 ◽  
Author(s):  
Siyi Yan ◽  
Peng Li ◽  
Zhongshi Ju ◽  
He Chen ◽  
Jiangang Ma

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.


2017 ◽  
Vol 5 (5) ◽  
pp. 1095-1105 ◽  
Author(s):  
Jun Li ◽  
Hu Liu ◽  
Jiang Guo ◽  
Zhen Hu ◽  
Zhijiang Wang ◽  
...  

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


2021 ◽  
Vol 875 ◽  
pp. 160-167
Author(s):  
Muhammad Fayzan Shakir ◽  
Asra Tariq

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.


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