A New CCM (Carbon Composite Matrix) Material with Improved Shielding Effectiveness for X-Band Application

2010 ◽  
Vol E93-C (6) ◽  
pp. 929-931 ◽  
Author(s):  
Yeong-Chul CHUNG ◽  
Kyung-Won LEE ◽  
Ic-Pyo HONG ◽  
Kyung-Hyun OH ◽  
Jong-Gwan YOOK
Keyword(s):  
Matrix Material ◽  
Carbon Composite ◽  
Shielding Effectiveness ◽  
Composite Matrix ◽  
X Band

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.

Electromagnetic shielding performance of three-dimensional woven fabrics with copper-based hybrid yarn in X-band frequency range

2018 ◽  
Vol 49 (4) ◽  
pp. 484-502 ◽  
Author(s):  
Dharmendra Nath Pandey ◽  
Arindam Basu ◽  
Pramod Kumar ◽  
Himangshu B Baskey
Keyword(s):  
Cotton Fabric ◽  
Three Dimensional ◽  
Electromagnetic Shielding ◽  
Shielding Effectiveness ◽  
Frequency Range ◽  
Structural Configuration ◽  
Band Frequency ◽  
Hybrid Yarn ◽  
X Band ◽  
Electromagnetic Shielding Effectiveness

This study involves a comprehensive evaluation of electromagnetic shielding characteristics of multilayer three-dimensional conductive fabrics by using cotton/copper wrapped hybrid yarn in X band frequency range. Five, three-dimensional fabrics with different structural configuration, such as orthogonal, angle interlock, cellular spacer, multi-tubular spacer, and contour were produced. Three different series of all five structures was also developed using pure cotton fabric, conductive hybrid yarn in weft and one-third hybrid yarn and two-third cotton yarn in warp Also, the effect of vertical and horizontal polarization of electromagnetic waves on electromagnetic shielding effectiveness was studied. The comparative analysis of reflectance transmittance and absorption behavior was also undertaken. The results indicate that pure cotton fabric (A series) does not have electromagnetic shielding capabilities. The difference between the electromagnetic shielding effectiveness values in vertical and horizontal planes of fabrics, having conductive hybrid yarn in weft direction (B series), showed significantly better results on the vertical plane in comparison to that on the horizontal plane. Fabric containing conductive hybrid yarn in both warp and weft (C series) exhibits consistent electromagnetic shielding effectiveness in both the planes. It is worth mentioning that the structural configuration in all five three-dimensional fabrics in B and C series has shown differential trends of electromagnetic shielding effectiveness in terms of reflectance, transmittance and absorption behavior. They are also found to be statistically significant. Finally, it is concluded that the conductive 3-D multilayer system develops special protective capabilities, mostly due to its larger surface area.

Reuse of Byproduct Alumina Composite Powder from Hydrogen Production Process

2015 ◽  
Vol 1119 ◽  
pp. 229-233
Author(s):  
K. Velmanirajan ◽  
R.S. Abinesh ◽  
S. Manoharan ◽  
K. Anuradha ◽  
R. Karunakaran ◽  
...  
Keyword(s):  
Composite Powder ◽  
Hydrogen Generation ◽  
Matrix Material ◽  
Fiber Reinforcement ◽  
Thermal Conditions ◽  
Vital Role ◽  
Plastic Behavior ◽  
Generation Process ◽  
Composite Matrix ◽  
Alumina Composite

Water molecule reacts with aluminium when it is immersed in water, which plays a vital role in hydrogen generation process. This process which uses sodium hydroxide as catalyst produces a byproduct alumina and some other scarce ingredients. This byproduct is mentioned as alumina composite powder (ACP). In an attempt of reutilizing and converting it into a matrix material using a resin polymer as a binder, this work investigates the workability of the product produced by alumina composite matrix. The specimen produced by alumina composite matrix has been tested for its desirable strength, namely, tensile strength, elongation under varied thermal conditions, compression test, flexural test with fiber reinforcement and non fiber reinforcement. The nature of crack formation and the plastic behavior of the specimen during test have been analyzed, based on the crack propagation in failure plane in the alumina composite matrix as a high quality alternative for wood and tiles for high class interior decorations. This research explores the effective use of the byproduct alumina composite matrix and its consistent eco-friendly nature.

scholarly journals Multilayered salt water with high optical transparency for EMI shielding applications

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Duy Tung Phan ◽  
Chang Won Jung
Keyword(s):  
Electromagnetic Interference ◽  
Light Transmission ◽  
Salt Water ◽  
Water Layer ◽  
Visual Observation ◽  
Optical Transparency ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Multilayered Structures ◽  
X Band

AbstractElectromagnetic interference (EMI) shielding for visual observation applications, such as windows utilized in military or aerospace, is important but difficult to realize due to conventional materials having difficulty in achieving sufficient transparency and EMI shielding simultaneously. In this paper, we present multilayered structures based on salt water for simultaneous highly optical transparency (OT) and EM shielding effectiveness (SE) performance. In the proposed structures, planar acrylic and glass were used as two types of clear substrates to hold salt water. The measured OT of both acrylic/salt water/acrylic and glass/salt water/glass structures was higher than 90% with a nearly uniform light transmission, which introduced a negligible impact on optical observation. Furthermore, both simulations and experimental results demonstrated that the SE of the multilayer structure was higher than 20 dB in the X-band from 7.5 to 8.5 GHz. Moreover, the SE was significantly enhanced by increasing the thickness of the salt water layer. Especially, both OT and SE of the multilayered structures were improved simultaneously by increasing the salinity of the salt water. These proposed structures demonstrate great potential in EMI shielding observation applications.

Flexible few-layered graphene/poly vinyl alcohol composite sheets: synthesis, characterization and EMI shielding in X-band through the absorption mechanism

RSC Advances ◽  
2015 ◽  
Vol 5 (46) ◽  
pp. 36498-36506 ◽  
Author(s):  
Sandeep K. Marka ◽  
Bashaiah Sindam ◽  
K. C. James Raju ◽  
Vadali V. S. S. Srikanth
Keyword(s):  
Electromagnetic Interference ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Composite Sheet ◽  
Absorption Mechanism ◽  
X Band ◽  
Electromagnetic Interference Shielding Effectiveness

An excellent electromagnetic interference shielding effectiveness of ∼19.5 dB was measured for a 1 mm thick flexible few-layered graphene (FLG)/PVA composite sheet owing to the formation of network-like features by FLG in the PVA matrix.

scholarly journals An Inexpensive Route to Synthesize High-Purity CrO2 for EMI Shielding in X-Band Frequencies

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Vivek Verma ◽  
Shahab Ahmad ◽  
Abdullah Dar ◽  
R. Kotnala
Keyword(s):  
High Purity ◽  
Microwave Frequency ◽  
External Pressure ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Frequency Range ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
X Band ◽  
Simplified Procedure

Rod-shaped high-purity samples of CrO2 have been synthesized by an inexpensive and simplified procedure. Here, we have prepared pure CrO2 without applying any external pressure or control it during synthesis. The sample prepared exhibited an improvement in saturation magnetization values, 68 emu/g at 300 K, 136 emu/g at 80 K, and uniform grained microstructure. The complex permittivity, permeability, and microwave absorption properties of high-purity CrO2 sample were investigated in the 8.2–12.2 GHz (X-band) microwave frequency range. Microwave measurements have shown the high shielding effectiveness due to absorption (SEA) of 20.3 dB. The high value of SEA suggests that CrO2 can be used as a promising electromagnetic shielding, EMI, material in 8.2–12.2 GHz (X-band) microwave frequency range.

scholarly journals ESTIMATION OF REFLECTIVITY AND SHIELDING EFFECTIVENESS OF THREE LAYERED LAMINATE ELECTROMAGNETIC SHIELD AT X-BAND

2010 ◽  
Vol 20 ◽  
pp. 205-223 ◽  
Author(s):  
C. Dharma Raj ◽  
G. Sasibhushana Rao ◽  
P. V. Y. Jayasree ◽  
B. Srinu ◽  
P. Lakshman
Keyword(s):  
Shielding Effectiveness ◽  
X Band ◽  
Electromagnetic Shield
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