Optically Transparent EMI Shielding Nanocomposite for X band

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.

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Multilayered salt water with high optical transparency for EMI shielding applications

Scientific Reports ◽

10.1038/s41598-020-78717-0 ◽

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.

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

RSC Advances ◽

10.1039/c5ra04038h ◽

2015 ◽

Vol 5 (46) ◽

pp. 36498-36506 ◽

Cited By ~ 20

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.

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Graphene nanoribbon–PVA composite as EMI shielding material in the X band

Nanotechnology ◽

10.1088/0957-4484/24/45/455705 ◽

2013 ◽

Vol 24 (45) ◽

pp. 455705 ◽

Cited By ~ 65

Author(s):

Anupama Joshi ◽

Anil Bajaj ◽

Rajvinder Singh ◽

P S Alegaonkar ◽

K Balasubramanian ◽

...

Keyword(s):

Graphene Nanoribbon ◽

Emi Shielding ◽

X Band ◽

Shielding Material

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

ISRN Materials Science ◽

10.5402/2012/948219 ◽

2012 ◽

Vol 2012 ◽

pp. 1-4 ◽

Cited By ~ 1

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.

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

Functional Materials Letters ◽

10.1142/s1793604720510248 ◽

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.

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