PANI-molybdate nanocomposites: Structural, morphological and dielectric properties for the effective electromagnetic interference (EMI) shielding applications in 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.

Download Full-text

Electromagnetic interference (EMI) shielding and microwave dielectric properties of (BaxMg1-x)(Ti0.95Sn0.05)O3 {x = 0.025 and 0.05} solid solutions in Ku-band

2019 IEEE MTT-S International Microwave and RF Conference (IMARC) ◽

10.1109/imarc45935.2019.9118729 ◽

2019 ◽

Author(s):

Jasdeep Singh ◽

Shalini Bahel

Keyword(s):

Dielectric Properties ◽

Solid Solutions ◽

Electromagnetic Interference ◽

Microwave Dielectric Properties ◽

Emi Shielding ◽

Microwave Dielectric ◽

Ku Band

Download Full-text

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.

Download Full-text

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.

Download Full-text

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.

Download Full-text

Layer-structured silver nanowire/polyaniline composite film as a high performance X-band EMI shielding material

Journal of Materials Chemistry C ◽

10.1039/c5tc04406e ◽

2016 ◽

Vol 4 (19) ◽

pp. 4193-4203 ◽

Cited By ~ 64

Author(s):

Fang Fang ◽

Yuan-Qing Li ◽

Hong-Mei Xiao ◽

Ning Hu ◽

Shao-Yun Fu

Keyword(s):

Electrical Conductivity ◽

Electromagnetic Interference ◽

High Performance ◽

Composite Films ◽

Silver Nanowire ◽

Emi Shielding ◽

Electromagnetic Interference Shielding ◽

X Band ◽

Pani Composite ◽

Shielding Material

The superiority of layer-structured Ag-NW/PANI composite films over the plain-structured in electrical conductivity and electromagnetic interference shielding.

Download Full-text

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

NANO ◽

10.1142/s1793292018500613 ◽

2018 ◽

Vol 13 (06) ◽

pp. 1850061 ◽

Cited By ~ 1

Author(s):

Shaowei Lu ◽

Yaoyao Bai ◽

Jijie Wang ◽

Chenxu Zhao ◽

Wei Li ◽

...

Keyword(s):

Electromagnetic Interference ◽

Energy Dispersive Spectrometer ◽

Composite Films ◽

Resin Matrix ◽

Manufacturing Cost ◽

Shielding Effectiveness ◽

Emi Shielding ◽

Filtration Method ◽

Emi Shielding Effectiveness ◽

X Band

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.

Download Full-text

Recycling and Reusing Polyethylene Waste as Antistatic and Electromagnetic Interference Shielding Materials

International Journal of Polymer Science ◽

10.1155/2020/6421470 ◽

2020 ◽

Vol 2020 ◽

pp. 1-15

Author(s):

Mostafizur Rahaman ◽

Ibrahim Abdullah Al Ghufais ◽

Govindasami Periyasami ◽

Ali Aldalbahi

Keyword(s):

Thermal Stability ◽

Dielectric Properties ◽

Carbon Black ◽

Electromagnetic Interference ◽

Mixing Time ◽

Waste Product ◽

Low Density Polyethylene ◽

Low Density ◽

Emi Shielding ◽

Scanning Calorimetry

The aim of this work is to manage the waste product based on polyethylene (PE) films by recycling and reusing it as antistatic material for electronic packaging and electromagnetic interference (EMI) shielding material for protecting electronic equipment from interference of EM radiation. To achieve this, a conductive carbon black has been mixed with the PE waste at different weight percent values by ultrasonication via a solution mixing process. Mixing time for sonication was determined by ultraviolet-visible (UV-VIS) spectra. A differential scanning calorimetry (DSC) study showed that the low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE) are immiscible in their blend composition. The tensile properties of PE have reduced substantially after reprocessing. However, the addition of carbon black has improved its strength up to a certain loading. The electrical percolation threshold values, calculated using the classical power law and sigmoidal Boltzmann model, were obtained at 3.5 and 2.8 wt% loading of carbon black, respectively. The conductivity result revealed that 1-2 wt% carbon-loaded composites can be used as antistatic material. The composites, having carbon loading above 4 wt%, can be effective materials for EMI shielding application. The 10 wt% carbon-loaded composite exhibits EMI SE value 33 dB which means there is approximately 99.93% protection of EM radiation at the sample thickness of 1.0 mm. Moreover, FTIR analysis, thermal stability, AC conductivity, dielectric properties, permeability, and current-voltage characteristics are also discussed in detail. There is a substantial increment in thermal stability, and dielectric properties are observed with the addition carbon black loading within the polymer matrix.

Download Full-text

Flexible GnPs/EPDM with Excellent Thermal Conductivity and Electromagnetic Interference Shielding Properties

NANO ◽

10.1142/s1793292019500759 ◽

2019 ◽

Vol 14 (06) ◽

pp. 1950075 ◽

Cited By ~ 2

Author(s):

Shaowei Lu ◽

Yaoyao Bai ◽

Jijie Wang ◽

Dandan Chen ◽

Keming Ma ◽

...

Keyword(s):

Thermal Conductivity ◽

Electromagnetic Interference ◽

Rubber Matrix ◽

Shielding Effectiveness ◽

Emi Shielding ◽

Emi Shielding Effectiveness ◽

X Band ◽

Cost Efficient ◽

Emi Se ◽

Shielding Material

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.

Download Full-text