scholarly journals Conducting Polymeric Composites Based on Intrinsically Conducting Polymers as Electromagnetic Interference Shielding/Microwave Absorbing Materials—A Review

2021 ◽  
Vol 5 (7) ◽  
pp. 173
Author(s):  
Bluma Guenther Soares ◽  
Guilherme M. O. Barra ◽  
Tamara Indrusiak
Keyword(s):  
Conducting Polymers ◽  
Electromagnetic Interference ◽  
Electromagnetic Shielding ◽  
Human Beings ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Preparation Methods ◽  
Microwave Absorbing Materials ◽  
Microwave Absorbing ◽  
Intrinsically Conducting Polymers

The development of sophisticated telecommunication equipment and other electro-electronic devices resulted in a kind of electromagnetic pollution that affects the performance of other equipment as well as the health of human beings. Intrinsically conducting polymers (ICP), mainly polyaniline and polypyrrole, have been considered as promising candidates for applications in efficient electromagnetic interference shielding (EMI) due to their ease of preparation, light weight, good conductivity and corrosion resistance. One of the important advantages of these materials is the capability to interact with the EM radiation through both absorption and reflection mechanisms thus enlarging the field of application. In this context, this review article describes a recent overview of the existing methods to produce intrinsically conducting polymers and their blends for electromagnetic shielding application. Additionally, it highlights the relationship between preparation methods reported in the literature with the structure and properties, such as electrical conductivity, electromagnetic shielding effectiveness (EMI SE), complex permittivity and permeability of these materials. Furthermore, a brief theory related to the electromagnetic mechanism and techniques for measuring the microwave absorbing properties are also discussed.

scholarly journals Multilayer-Structured Wood Electroless Cu–Ni Composite Coatings for Electromagnetic Interference Shielding

Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 740
Author(s):  
Yanfei Pan ◽  
Dingwen Yin ◽  
Xiaofang Yu ◽  
Nanyi Hao ◽  
Jintian Huang
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Electromagnetic Interference ◽  
Composite Coatings ◽  
Electromagnetic Shielding ◽  
Shielding Effectiveness ◽  
Frequency Range ◽  
Electromagnetic Interference Shielding ◽  
Electromagnetic Shielding Effectiveness ◽  
The Ideal

The lightweight multilayer-structured electromagnetic interference shielding composite coatings with controllable electromagnetic gradient on wood surface were prepared via a simple multiple electroless copper–nickel (Cu–Ni) approach. The surface morphology, conductivity, hydrophobicity property and electromagnetic shielding effectiveness of the composite coatings were investigated. The surface roughness and conductivity of the composite coatings were enhanced with the increase in the number of depositions. The surface morphology demonstrated that the roughness was decreased with the process of multiple electroless. The coatings were compact and homogeneous as the deposition run was three. Here, the Sa (Sa illustrated Surface Roughness) value of coatings was 4.497 μm. The ideal conductivity of composite coatings can be obtained as the number of depositions was four. Electromagnetic shielding effectiveness reached average 90.69 dB in the frequency range from 300 kHz to 2.0 GHz. This study provides a new pathway for fabricating lightweight multilayer-structured electromagnetic interference shielding with controllable electromagnetic gradient and hydrophobic composite coatings-based wood.

scholarly journals Electromagnetic Interference Shielding of Metal Coated Ultrathin Nonwoven Fabrics and Their Factorial Design

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 484
Author(s):  
Sundaramoorthy Palanisamy ◽  
Veronika Tunakova ◽  
Shi Hu ◽  
Tao Yang ◽  
Dana Kremenakova ◽  
...  
Keyword(s):  
Design Of Experiment ◽  
Electromagnetic Interference ◽  
Nonwoven Fabric ◽  
Electromagnetic Shielding ◽  
Material Structure ◽  
Main Role ◽  
Geometrical Shape ◽  
Human Beings ◽  
Shielding Effectiveness ◽  
Screening Design

Electromagnetic (EM) radiation is everywhere in this world and galaxy in different forms and levels. In some cases, human beings need to protect themselves from electromagnetic radiations and the same thing is also recommended for electronic devices as well. Lots of studies are there on the shielding of electromagnetic radiation interference using metals, polymers, and minerals. For protecting the human being, textile structures are playing the main role. In the textile material structure itself many types are there; each one is having its unique geometrical shape and design. In this work, the copper/nickel-coated ultrathin nonwoven fabric is prepared like a strip. The 3, 6, and 9 mm thick strips are prepared and laid at different gaps, angles, and layered to study the effect of factors on EM shielding effectiveness as per ASTM D4935-10 standard. The design of experiment has been done to analyze the three factors and three levels of the strip properties having an influence on electromagnetic shielding results. From the findings of the design of experiment (DoE) screening design, the factors are the thickness of the strips, the gap between the strips, and the strips laid angle having a statistically significant effect on electromagnetic shielding effectiveness.

Synergistic effects of hybrid conductive fillers on the electrical properties of carbon fiber pultruded polypropylene/polycarbonate composites prepared by injection molding

2016 ◽  
Vol 51 (7) ◽  
pp. 1005-1017 ◽  
Author(s):  
Myung Geun Jang ◽  
Choonglai Cho ◽  
Woo Nyon Kim
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Carbon Fiber ◽  
Injection Molding ◽  
Electromagnetic Interference ◽  
Synergistic Effects ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Preparation Methods ◽  
Electromagnetic Interference Shielding Effectiveness

In this study, the effects of filler characteristics and composite preparation methods on the morphology, mechanical property, electrical conductivity, and electromagnetic interference shielding effectiveness of the polypropylene/polycarbonate (70/30, wt%)/hybrid conductive filler composites were investigated. Nickel-coated carbon fiber (NCCF) was used as main filler and TiO2, multi-walled carbon nanotube, and graphite were used as second fillers in the composites. The pultruded NCCF/polypropylene composite was used in the preparation of the polypropylene/polycarbonate/NCCF/second filler composites. The electrical conductivity and electromagnetic interference shielding effectiveness of the polypropylene/polycarbonate/NCCF/second filler composites were compared with the type of second filler. The superior value of electromagnetic interference shielding effectiveness was observed to be 51.6 dB (decibel) when the hybrid fillers such as NCCF (5.2 vol% or 20 wt%) and TiO2 (1.2 vol% or 5 wt%) were added in the polypropylene/polycarbonate (70/30) composite. The electrical properties of the polypropylene/polycarbonate (70/30)/NCCF/TiO2 composites was compared with the composite preparation methods, which were injection molding and screw extrusion. The results suggested that fiber length of the NCCF affected significantly to the electrical conductivity and electromagnetic interference shielding effectiveness of the polypropylene/polycarbonate (70/30)/NCCF/TiO2 composites.

scholarly journals Electromagnetic interference shielding characteristics of a core layer-coated fabric with excellent hand-feel characteristics

2020 ◽  
Vol 15 ◽  
pp. 155892502095973
Author(s):  
D Xu ◽  
WW Yang ◽  
HM Jiang ◽  
H Fan ◽  
KS Liu
Keyword(s):  
Surface Layer ◽  
Electromagnetic Interference ◽  
Core Layer ◽  
Polyvinyl Butyral ◽  
Electromagnetic Shielding ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Electron Microscopic ◽  
The Core ◽  
Coated Fabric

Electromagnetic shielding fabric (ESF) is a novel electromagnetic shielding product with portability, flexibility, and good mechanical properties. However, the existing ESFs suffer from poor washing fastness of coating and poor comfort performance in terms of hand-feel characteristic. In this study, a core layer-coated yarn (CLCY) was successfully spun using a carboxylic acid-functionalized multi-walled carbon nanotube/polypyrrole/Fe3O4 composite suspension with polyvinyl butyral as an adhesive agent. To better explore the properties, the original fabric and treated fabrics, viz., core layer-coated fabric (CLCF) and surface layer-coated fabric (SLCF), were characterized by several methods. Scanning electron microscopic observations revealed that the coating was on the core layer in CLCF. In addition, the Fourier-transform infrared spectroscopy and X-ray diffraction spectroscopy results revealed that the composition of the coating corresponds with that in the multi-composite suspension. Moreover, the coating of CLCY formed a conductive path with good conductivity in the core layer, but the conductivity of the coating on the surface layer of SLCF deteriorated sharply after washing. Further, compared with the original fabric and SLCF, CLCF has highest breaking strength (after 10 washes), and keeps a relatively good hand-feel characteristic. Finally, the evaluated electromagnetic interference shielding characteristics reveal that the fastness of coating affects the electromagnetic shielding effectiveness, suggesting that the wrapped protection of outside staple fibers in CLCF reduce the loss of coating in the core layer during washing. However, the coating on the surface layer in SLCF could be washed away easily.

scholarly journals Interface Engineered Microcellular Magnetic Conductive Polyurethane Nanocomposite Foams for Electromagnetic Interference Shielding

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Guolong Sang ◽  
Pei Xu ◽  
Tong Yan ◽  
Vignesh Murugadoss ◽  
Nithesh Naik ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Magnetic Loss ◽  
Interfacial Polarization ◽  
Conductive Network ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Multiple Reflections ◽  
Conduction Loss ◽  
Composite Foams ◽  
Emi Se

Abstract Lightweight microcellular polyurethane (TPU)/carbon nanotubes (CNTs)/ nickel-coated CNTs (Ni@CNTs)/polymerizable ionic liquid copolymer (PIL) composite foams are prepared by non-solvent induced phase separation (NIPS). CNTs and Ni@CNTs modified by PIL provide more heterogeneous nucleation sites and inhibit the aggregation and combination of microcellular structure. Compared with TPU/CNTs, the TPU/CNTs/PIL and TPU/CNTs/Ni@CNTs/PIL composite foams with smaller microcellular structures have a high electromagnetic interference shielding effectiveness (EMI SE). The evaporate time regulates the microcellular structure, improves the conductive network of composite foams and reduces the microcellular size, which strengthens the multiple reflections of electromagnetic wave. The TPU/10CNTs/10Ni@CNTs/PIL foam exhibits slightly higher SE values (69.9 dB) compared with TPU/20CNTs/PIL foam (53.3 dB). The highest specific EMI SE of TPU/20CNTs/PIL and TPU/10CNTs/10Ni@CNTs/PIL reaches up to 187.2 and 211.5 dB/(g cm−3), respectively. The polarization losses caused by interfacial polarization between TPU substrates and conductive fillers, conduction loss caused by conductive network of fillers and magnetic loss caused by Ni@CNT synergistically attenuate the microwave energy.

scholarly journals Lightweight Cellulose/Carbon Fiber Composite Foam for Electromagnetic Interference (EMI) Shielding

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1319 ◽  
Author(s):  
Ran Li ◽  
Huiping Lin ◽  
Piao Lan ◽  
Jie Gao ◽  
Yan Huang ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Electromagnetic Interference ◽  
Fiber Composite ◽  
Carbon Fiber Composites ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Carbon Fiber Composite ◽  
Foaming Process ◽  
Long Carbon Fibers

Lightweight electromagnetic interference shielding cellulose foam/carbon fiber composites were prepared by blending cellulose foam solution with carbon fibers and then freeze drying. Two kinds of carbon fiber (diameter of 7 μm) with different lengths were used, short carbon fibers (SCF, L/D = 100) and long carbon fibers (LCF, L/D = 300). It was observed that SCFs and LCFs built efficient network structures during the foaming process. Furthermore, the foaming process significantly increased the specific electromagnetic interference shielding effectiveness from 10 to 60 dB. In addition, cellulose/carbon fiber composite foams possessed good mechanical properties and low thermal conductivity of 0.021–0.046 W/(m·K).

Realization of electromagnetic shielding performance for polyimide-matrix composite by self-metallization

2021 ◽  
pp. 002199832110316
Author(s):  
Jiayang Zhang ◽  
Hongjiang Ni ◽  
Ming Gong ◽  
Jun Li ◽  
Daijun Zhang ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Matrix Composite ◽  
Electromagnetic Interference ◽  
Interfacial Strength ◽  
Amic Acid ◽  
Thermal Reduction ◽  
Electromagnetic Shielding ◽  
Shielding Effectiveness ◽  
Heat Condition ◽  
Electromagnetic Interference Shielding Effectiveness

Electromagnetic shielding performance has been achieved for a polyimide (PI)-matrix composite by the strategy of self-metallization of its thermosetting PI matrix. Self-metallization of the thermosetting PI was realized by silver ion/poly(amic acid) (PAA) precursor ion exchange and thermal reduction. The factors influencing the self-metallization were investigated. The electrical conductivity and integrity for the surface of the PI were achieved by optimization of ion exchange/thermal reduction parameters. The fabricated PI-matrix composite exhibits a maximum electromagnetic interference shielding effectiveness value of 81 dB. Importantly, the electromagnetic shielding performance can be maintained even after heat condition of 300°C. Meanwhile, the surface-metallized PI composite exhibits mechanical property equivalent to the pristine composite, and an Ag/matrix interfacial strength higher than 19.6 MPa. Besides, self-metallization mechanism of the thermosetting PI was investigated.

Sign in / Sign up

Export Citation Format

Share Document