scholarly journals Effects of the Carbon Fiber-Carbon Microcoil Hybrid Formation on the Effectiveness of Electromagnetic Wave Shielding on Carbon Fibers-Based Fabrics

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2344 ◽  
Author(s):  
Hyun-Ji Kim ◽  
Sung-Hoon Kim ◽  
Sangmoon Park
Keyword(s):  
Electromagnetic Wave ◽  
Carbon Fiber ◽  
Nonwoven Fabric ◽  
Woven Fabrics ◽  
Dramatic Improvement ◽  
Shielding Effectiveness ◽  
Absorption Mechanism ◽  
Nonwoven Fabrics ◽  
Hybrid Formation ◽  
Electrical Conductivities

Carbon fiber-carbon microcoil (CF-CMC) hybrids were formed on carbon fiber (CF)-based fabric. The morphologies of CF-based fabrics and CF-CMC hybridized fabrics were investigated. The electrical conductivities of the CF-CMC hybridized fabrics were examined and compared with those of native CF-based fabrics. Furthermore, the electromagnetic wave shielding effectiveness (SE) of the CF-CMC hybridized fabrics was investigated across operating frequencies in the 8.0–12.0 GHz range, and the results were compared with those for native CF-based fabrics. For the CF-based nonwoven fabrics, the SE values were improved by the CF-CMC hybridization reaction, although the electrical conductivities of the nonwoven fabric were reduced by the CF-CMC hybrid formation. For the CF-based woven fabrics, the SE values were improved by more than twofold throughout the entire range of frequencies, owing to the CF-CMC hybrid formation. This dramatic improvement was partly ascribed to the enhanced electrical conductivity, particularly in the transverse direction to the individual CFs. Owing to the increased thickness of the woven or nonwoven fabrics after the CF-CMC hybrid formation and the intrinsic characteristics of CMCs, the absorption mechanism for the SE was determined for the main factor that contributed to the improvement of the SE values.

scholarly journals Enhancement in Electromagnetic Wave Shielding Effectiveness through the Formation of Carbon Nanofiber Hybrids on Carbon-Based Nonwoven Fabrics

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2910
Author(s):  
Hyun-Ji Kim ◽  
Gi-Hwan Kang ◽  
Sung-Hoon Kim ◽  
Sangmoon Park
Keyword(s):  
Electromagnetic Wave ◽  
Gas Flow ◽  
Carbon Nanofiber ◽  
Chemical Vapor ◽  
Absorption Enhancement ◽  
Dramatic Improvement ◽  
Shielding Effectiveness ◽  
Nonwoven Fabrics ◽  
Hybrid Formation ◽  
Carbon Based

The selective hybrid formation of numerous tiny carbon nanofibers (CNFs) in carbon-based nonwoven fabrics (c-NFs), namely CNFs formed only on the surfaces of individual carbon fibers (i-CFs) constituting c-NFs and not on the surfaces of carbon microcoils (CMCs), could be formed by the incorporation of H2 gas flow into the C2H2 + SF6 gas flow in a thermal chemical vapor deposition system. On the other hand, the nonselective hybrid formation of numerous tiny CNFs in c-NFs, that is, tiny CNFs formed on the surfaces of both i-CFs and CMCs, could be achieved by simply modulating the SF6 gas flow on and off in continuous cycles during the reaction. Detailed mechanisms are suggested for the selective or nonselective formation of tiny CNFs in c-NFs. Furthermore, the electromagnetic wave shielding effectiveness (SE) values of the samples were investigated across operating frequencies in the 8.0–12.0 GHz range. Compared with previously reported total SE values, the presently measured values rank in the top tier. Although hybrid formation reduced the electrical conductivity of the native c-NFs, the total SE values of the native c-NFs greatly increased following hybrid formation. This dramatic improvement in the total SE values is ascribed to the increased thickness of c-NFs after hybrid formation and the electromagnetic wave absorption enhancement caused by the intrinsic characteristics of CMCs and the numerous intersections of tiny CNFs.

Electromagnetic Wave Shieding Effectiveness of Carbon Fiber Sheet Coated Ferrite Film by Microwave-Hydrothermal Process

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1235-1241 ◽  
Author(s):  
Ri Ichi Murakami ◽  
Hidetoshi Yamamoto ◽  
Chan Kong Kim ◽  
Cheol Mun Yim ◽  
Yun Hae Kim
Keyword(s):  
Electromagnetic Wave ◽  
Carbon Fiber ◽  
Wireless Lan ◽  
Hydrothermal Process ◽  
Ferrite Film ◽  
Shielding Effectiveness ◽  
Microwave Hydrothermal ◽  
Fiber Sheet ◽  
Coated Carbon ◽  
Carbon Fiber Sheet

The developments of electromagnetic wave shielding materials are strongly required because the malfunction of electronic equipment, mobile phone and wireless LAN avoids. In this study, it was investigated that the electromagnetic shielding effectiveness of carbon fiber sheets were enhanced by the ferrite which was coated by the microwave hydrothermal process. For coated carbon fiber sheet, the effects of ferrite and lamination of carbon fiber textile on the electromagnetic wave shielding effectiveness were discussed. In the range of frequency (100 – 1 GHz), the electromagnetic wave shielding effectiveness was measured by using TEM-Cell. The electromagnetic wave shielding effectiveness was greater for the coated carbon fiber sheets than for the uncoated carbon fiber sheets. When the insulation film was located between two carbon fiber sheets, the electromagnetic wave shielding effectiveness increased.

Preparation and properties of multifunctional nylon 6 composite material

2011 ◽  
Vol 45 (26) ◽  
pp. 2707-2715 ◽  
Author(s):  
Lai Chiu-Chun ◽  
Jen Chyi-Wen ◽  
Chang Yuh-Shyang ◽  
Huang Kuo-Shien
Keyword(s):  
Composite Material ◽  
Electromagnetic Wave ◽  
Carbon Fiber ◽  
Imaging System ◽  
Base Material ◽  
Negative Ions ◽  
Negative Ion ◽  
Shielding Effectiveness ◽  
Ion Release ◽  
Osmotic Concentration

We considered polyamide 6 as a base material for a composite and added improved tourmaline and carbon fiber to manufacture a material that could release negative ions and resist electromagnetic waves. Through Fourier transform infrared spectroscopy and thermogravimetric analyses, we verified that the improved tourmaline could disperse homogeneously in the base material, whose thermal properties improved as the content of tourmaline increased. Scanning electron microscopy demonstrated that the added tourmaline and carbon fiber complemented the conductive network of the composite material. A negative ion detector and an infrared thermal imaging system both revealed that with an appropriate tourmaline content, the negative ion release properties of the composite material could reach 2020 units cm−3 with a difference in temperature of up to 7.54°C. Analyses by a four-point probe low-resistance tester and electromagnetic wave shielding effectiveness tester demonstrated that the osmotic concentration was approximately 4%, and the surface resistivity was high, up to 1.04 × 107 Ω cm−1, reaching the range of static dissipative materials (106–1012 Ω cm−1). The maximum electromagnetic wave shielding effectiveness was as high as 30 dB MHz−1.

Experimental and statistical analysis of carbon fiber/epoxy composites interleaved with nylon 6,6 nonwoven fabric interlayers

2020 ◽  
Vol 54 (27) ◽  
pp. 4173-4184
Author(s):  
Bertan Beylergil ◽  
Metin Tanoğlu ◽  
Engin Aktaş
Keyword(s):  
Fracture Toughness ◽  
Carbon Fiber ◽  
Composite Laminates ◽  
Nonwoven Fabric ◽  
Epoxy Composites ◽  
Nonwoven Fabrics ◽  
Mode I Fracture Toughness ◽  
Weight Density ◽  
Nylon 6,6 ◽  
Carbon Fiber Epoxy

Thermoplastic interleaving is a promising technique to improve delamination resistance of laminated composites. In this study, plain-weave carbon fiber/epoxy composites were interleaved with nylon 6,6 nonwoven fabrics with an areal weight density of 17 gsm. The carbon fiber/epoxy composite laminates with/without nylon 6,6 nonwoven fabric interlayers were manufactured by VARTM technique. Double cantilever beam fracture toughness tests were carried out on the prepared composite test specimens in accordance with ASTM 5528 standard. The experimental test data were statistically analyzed by two-parameter Weibull distribution. The results showed that the initiation and propagation fracture toughness Mode-I fracture toughness of carbon fiber/epoxy composites could be improved by about 34 and 156% (corresponding to a reliability level of 0.50) with the incorporation of nylon 6,6 interlayers in the interlaminar region, respectively. The results also revealed that the percent increase in the propagation fracture toughness value was 67 and 41% at reliability levels of 0.90 and 0.95, respectively.

Mechanical and Electrical Properties of the Polyaniline (PANI)/Polylactic Acid (PLA) Nonwoven Fabric

2013 ◽  
Vol 365-366 ◽  
pp. 1074-1077 ◽  
Author(s):  
Chin Mei Lin ◽  
Ching Hui Lin ◽  
Yu Tien Huang ◽  
Ching Wen Lou ◽  
Jia Horng Lin
Keyword(s):  
Mechanical Properties ◽  
Electromagnetic Wave ◽  
Melting Point ◽  
Polylactic Acid ◽  
Nonwoven Fabric ◽  
Consumer Products ◽  
Layer Number ◽  
Nonwoven Fabrics ◽  
Mechanical And Electrical Properties ◽  
Needle Punching

Technical development and rapid telecommunication create convenient consumer products, but produce electromagnetic radiation that hurts the human body, which makes the development of antistatic and electromagnetic-wave-resistant textiles important. This study combines polylactic acid (PLA) fibers and low melting point polylactic (LPLA) fibers by needle punching to make PLA nonwoven fabrics. The lamination layer number is then changed to explore its influence on the mechanical properties of the PLA nonwoven fabrics. Next, the nonwoven fabrics are spray-coated with polyaniline (PANI) to form the PANI/PLA nonwoven fabrics. The PANI/PLA nonwoven fabric with a lamination layer number of 5 has the optimum tensile and tear strength. A coating of PANI can reduce the surface resistivity.

A new study on the influencing factors and mechanism of shielding effectiveness of woven fabrics containing stainless steel fibers

2019 ◽  
Vol 50 (6) ◽  
pp. 830-846
Author(s):  
Yalan Yang ◽  
Jianping Wang ◽  
Zhe Liu ◽  
Zhujun Wang
Keyword(s):  
Stainless Steel ◽  
Electromagnetic Wave ◽  
Electromagnetic Radiation ◽  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
Living Environment ◽  
Steel Fibers ◽  
Wave Frequency ◽  
Shielding Effectiveness ◽  
Electromagnetic Shielding Effectiveness

Electromagnetic radiation is becoming increasingly serious around our living environment, which seriously endangers people's health and interferes with the operation of electronic equipment. The research and development of anti-electromagnetic radiation fabric have drawn more and more attention. However, the influencing rules and mechanisms of conductive fiber content, fabric tightness, warp–weft density, conductive yarn arrangement, weave type, and electromagnetic wave frequency on fabric electromagnetic shielding effectiveness have not been clarified. Therefore, in this study, a series of fabrics containing stainless steel fibers were produced. Meanwhile, the influencing rules of various factors on electromagnetic shielding effectiveness and the quantitative relationship between some factors and electromagnetic shielding effectiveness were discussed. The results showed that all factors had different degrees of influence on electromagnetic shielding effectiveness, and the relationship between electromagnetic shielding effectiveness and electromagnetic wave frequency could be approximately expressed as: [Formula: see text]. At the same time, the influencing mechanisms of various factors on electromagnetic shielding effectiveness were analyzed in combination with fabric microstructure and macrostructure, the intrinsic parameters of the fabric and the electromagnetic shielding effectiveness mechanism. The results are expected to provide a reference for the establishment of electromagnetic shielding fabric model and enterprise production.

The Effect of Singeing Calendering Processing on Properties of Filter Needled Nonwoven Fabrics

2013 ◽  
Vol 864-867 ◽  
pp. 605-612
Author(s):  
Xin Cui ◽  
Wei Min Xiao ◽  
Qin Fei Ke
Keyword(s):  
Nonwoven Fabric ◽  
Air Permeability ◽  
Woven Fabrics ◽  
Nonwoven Fabrics

To improve the quality of needled nonwoven for filtration, many companies will finish the nonwoven fabric in order to improve its performance. The process of singeing with calendering finishing is very important to improve its performance, after finishing the internal filter to a certain extent been blocked, reducing the pressure when cleaning, thereby extending the life of fabrics. We used different methods to deal with needle non-woven fabrics for filtration, which including singeing and singeing with calendering. Then we tested the strength, air permeability, weight and other properties of untreated samples, only singeing samples and singeing with calendering samples. The paper analyzed how treatments affect the properties of needle non-woven fabrics for filtration.

scholarly journals MoS2-Decorated/Integrated Carbon Fiber: Phase Engineering Well-Regulated Microwave Absorber

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Jing Yan ◽  
Ying Huang ◽  
Xiangyong Zhang ◽  
Xin Gong ◽  
Chen Chen ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Carbon Fiber ◽  
Microwave Absorption ◽  
Hydrothermal Route ◽  
Absorption Mechanism ◽  
Guest Molecules ◽  
The Matrix ◽  
One Step ◽  
New Type ◽  
Phase Engineering

AbstractPhase engineering is an important strategy to modulate the electronic structure of molybdenum disulfide (MoS2). MoS2-based composites are usually used for the electromagnetic wave (EMW) absorber, but the effect of different phases on the EMW absorbing performance, such as 1T and 2H phase, is still not studied. In this work, micro-1T/2H MoS2 is achieved via a facile one-step hydrothermal route, in which the 1T phase is induced by the intercalation of guest molecules and ions. The EMW absorption mechanism of single MoS2 is revealed by presenting a comparative study between 1T/2H MoS2 and 2H MoS2. As a result, 1T/2H MoS2 with the matrix loading of 15% exhibits excellent microwave absorption property than 2H MoS2. Furthermore, taking the advantage of 1T/2H MoS2, a flexible EMW absorbers that ultrathin 1T/2H MoS2 grown on the carbon fiber also performs outstanding performance only with the matrix loading of 5%. This work offers necessary reference to improve microwave absorption performance by phase engineering and design a new type of flexible electromagnetic wave absorption material to apply for the portable microwave absorption electronic devices.

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