scholarly journals Resistance against Penetration of Electromagnetic Radiation for Ultra-light Cu/Ni-Coated Polyester Fibrous Materials

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2029
Author(s):  
Kai Yang ◽  
Aravin Prince Periyasamy ◽  
Mohanapriya Venkataraman ◽  
Jiri Militky ◽  
Dana Kremenakova ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Electromagnetic Waves ◽  
Air Permeability ◽  
Ultraviolet Rays ◽  
Fibrous Materials ◽  
Shielding Effectiveness ◽  
Protection Factor ◽  
Water Contact ◽  
Ultraviolet Protection Factor ◽  
Coated Fabrics

Resistance against penetration of various rays including electromagnetic waves (EM), infrared rays (IR), and ultraviolet rays (UV) has been realized by using copper (Cu)-coated fabrics. However, the corrosion of the Cu on coated fabrics influenced the shielding effectiveness of the various rays. Besides, the metal-coated fabrics have high density and are unbreathable. This work aims to solve the problem by incorporating nickel (Ni) into the Cu coating on the ultra-light polyester fibrous materials (Milife® composite nonwoven fabric—10 g/m2, abbreviation Milife) via electroless plating. The electromagnetic interference (EMI), IR test, ultraviolet protection factor (UPF), water contact angle, and air permeability of the Cu/Ni-coated Milife fabric were measured. All the samples were assumed as ultra-light and breathable by obtaining the similar fabric density (~10.57 g/m2) and large air permeability (600–1050 mm/s). The Cu/Ni deposition on the Milife fabrics only covered the fibers. The EM shielding effectiveness (SE) decreased from 26 to 20 dB, the IR reflectance (Rinfrared) decreased from 0.570 to 0.473 with increasing wNi from 0 to 19.5 wt %, while the wNi improved the UPF from 9 to 48. Besides, addition of Ni changed the Cu/Ni-coated Milife fabric from hydrophilicity to the hydrophobicity by observing WCA from 77.7° to 114°.

scholarly journals A Silver Yarn-Incorporated Song Brocade Fabric with Enhanced Electromagnetic Shielding

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3779
Author(s):  
Xiuling Zhang ◽  
Zimin Jin ◽  
Lizhu Hu ◽  
Xinyi Zhou ◽  
Kai Yang ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Surface Resistance ◽  
Evaporation Rate ◽  
Uv Light ◽  
Air Permeability ◽  
Electromagnetic Shielding ◽  
Water Evaporation ◽  
Shielding Effectiveness ◽  
Protection Factor ◽  
Two Samples

The fabrics with electromagnetic interference (EMI) have been used in various fields. However, most studies related to the EMI fabrics focused on the improvement of the final electromagnetic shielding effectiveness (EM SE) by adjusting the preparation parameters while the breathability of the EMI fabrics was affected and the visible surficial patterns on the EMI fabric was limited. In this work, the two samples based on the Song Brocade structure were fabricated with surficial visible pattern ‘卐’. One was fabricated with silver-plated polyamide (Ag-PA) yarns and the silk yarns, the another with polyester (PET) yarns and the silk yarns. The weaving structure of the two samples were investigated by scanning electronic microscopy (SEM) and laser optical microscopy (LOM). The resistance against the EM radiation near field communication (NFC) and the ultraviolet (UV) light was also evaluated. Besides, the surface resistance, the air permeability and the water evaporation rate were investigated. The results revealed that the ‘卐’ appeared successfully on the surface of the two samples with stable weaving structure. The Ag-PA yarn-incorporated Song Brocade fabric had the EMI shielding effectiveness value around 50 dB, which was supported by the low surface resistance less than 40 Ω. The excellent NFC shielding of the Ag-PA yarn-incorporated Song Brocade was also found. The ultraviolet protection factor (UPF) value of the Ag-PA yarn-incorporated Song Brocade fabric was higher than 190. The air permeability and the evaporation rate of the Ag-PA yarn-incorporated Song Brocade fabric was higher than 99 mm/s, and 1.4 g/h, respectively. As a result, the Ag-PA yarn-incorporated Song Brocade fabrics were proposed for both the personal and the industrial scale utilization.

scholarly journals Structure and Functions of Cocoons Constructed by Eri Silkworm

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2701
Author(s):  
Bin Zhou ◽  
Huiling Wang
Keyword(s):  
Ultraviolet Rays ◽  
Structure Property ◽  
Buffer Effect ◽  
Protection Factor ◽  
Secondary Fracture ◽  
Ultraviolet Protection Factor ◽  
Air Gaps ◽  
Performance Indexes ◽  
Before And After ◽  
And Function

Eri silkworm cocoons (E cocoons) are natural composite biopolymers formed by continuous twin silk filaments (fibroin) bonded by sericin. As a kind of wild species, E cocoons have characteristics different from those of Bombyx mori cocoons (B cocoons). E cocoons have an obvious multilayer (5–9 layers) structure with an eclosion hole at one end and several air gaps between the layers, which can be classified into three categories—cocoon coat, cocoon layer, and cocoon lining—with varying performance indexes. There is a significant secondary fracture phenomenon during the tensile process, which is attributed to the high modulus of the cocoon lining and its dense structure. Air gaps provide cocoons with distinct multistage moisture transmission processes, which form a good moisture buffer effect. Temperature change inside cocoons is evidently slower than that outside, which indicates that cocoons also have an obvious temperature damping capability. The eclosion hole does not have much effect on heat preservation of E cocoons. The high sericin content of the cocoon coat, as well as the excellent ultraviolet absorption and antimicrobial abilities of sericin, allows E cocoons to effectively prevent ultraviolet rays and microorganisms from invading pupae. The ultraviolet protection factor (UPF) of the E cocoon before and after degumming were found to be 17.8% and 9.7%, respectively, which were higher than those of the B cocoon (15.3% and 4.4%, respectively), indicating that sericin has a great impact on anti-UV performance. In the cocoon structure, the outer layer of the cocoon has 50% higher content than the inner layer, and the E cocoon shows stronger protection ability than the B cocoon. Understanding the relationship between the structure, property, and function of E cocoons will provide bioinspiration and methods for designing new composites.

Experimental Investigation of the Electromagnetic Signal Attenuation Characteristics of the Partial Discharge Laboratory at Jadavpur University

2008 ◽  
Vol 9 (2) ◽  
Author(s):  
Biswendu Chatterjee ◽  
Debangshu Dey ◽  
Sivaji Chakravorti ◽  
Chinmoy Kanti Roy
Keyword(s):  
Magnetic Material ◽  
Electromagnetic Interference ◽  
Electromagnetic Waves ◽  
Real Life ◽  
Electromagnetic Signal ◽  
Shielding Effectiveness ◽  
Signal Attenuation ◽  
Conducting Material ◽  
Communication Signals ◽  
Attenuation Characteristics

Electromagnetic interference is becoming an increasing concern, because of the high intensity of surrounding electromagnetic waves, mainly arising from communication signals and also due to widespread use of equipment that operates at radio frequencies. As a consequence, sensitive data acquisition equipment suffers from erroneous results. Operating such instruments in a suitable shielded environment can significantly reduce this electromagnetic interference. But to achieve good shielding in practice, construction-related problems are to be faced, especially in large spaces, where a single metal plate cannot cover the whole area. Unless special care is taken, electromagnetic waves can penetrate through the gap in the joints and defects like drill holes reducing the shielding effectiveness. Also, a single layer of shielding is not always effective as the quality deteriorates drastically even due to minor constructional defects as mentioned above. This paper describes real-life experiences, step-by-step, in the shielding of a spacious insulation diagnostic laboratory (with a target of at least 55 dB signal attenuation), firstly using a good conducting material, using two different methods for joining the sheets, and ultimately constructing a second layer of shielding using a magnetic material. To study the attenuation behavior of the laboratory with respect to electromagnetic waves, a device for the relative measurement of surrounding electromagnetic signal strength is developed. The signal levels are measured initially outside and then at different places inside the shielded laboratory. The results presented in this paper show (1) the variation of attenuation characteristics inside the shielded laboratory due to different methods adopted for joining the shielding sheets using a good conducting material, (2) the effect of a second shielding layer in the form of a box that was constructed using a magnetic material and placed inside the laboratory and (3) the improvement in attenuation behavior after the actual construction of the second layer of shielding using a magnetic material.

Electromagnetic Shielding Effectiveness of Physical Property PET/Stainless Steel Composite Fabrics

2014 ◽  
Vol 910 ◽  
pp. 210-213 ◽  
Author(s):  
Jia Horng Lin ◽  
Ting An Lin ◽  
An Pang Chen ◽  
Ching Wen Lou
Keyword(s):  
Electromagnetic Waves ◽  
Physical Property ◽  
Electrical Equipment ◽  
Air Permeability ◽  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
Woven Fabric ◽  
Shielding Effectiveness ◽  
Composite Yarn ◽  
Electromagnetic Shielding Effectiveness

The electronic appliance is capable of emitting electromagnetic waves that will cause the damage of electrical equipment and influence peoples health. In this study, stain steel filament (SS filament) and 75D PET filament were used to manufacture SS/PET composite yarn The SS/PET composite yarn were made by the wrapping machine, which the core yarn is stain steel filament, wrapped yarn is 75D PET filament and the wrapping layers is varied as one and two. After that, the composite yarn is fabricated by the automatic sampling loom into composite woven fabrics. The composite SS/PET woven fabrics were under the tests of electromagnetic shielding effectiveness (EMSE) and air permeability. The test results revealed that the EMSE of the one-layer composite woven fabric is 9.5 dB at 900 MHz, but the EMSE decreases as test frequency increases. When laminating layer added to three layers, the EMSE raise up to 12.6 dB. The EMSE of composite woven fabric reached at 29.9 when the laminated angle is 45°. And the air permeability decreases as the laminate layer increases, which the thickness of sample affect air to pass through the sample.

scholarly journals Impact of Fabric Density, Color and Composition of Plain weave Fabric on Ultraviolet Protective Factor

2019 ◽  
pp. 13-15
Author(s):  
Marzia Islam ◽  
Tarifun Akter ◽  
Jannatul Ferdush ◽  
Kamrunnahar Kamrunnahar
Keyword(s):  
Protective Factor ◽  
Woven Fabric ◽  
Experimental Result ◽  
Ultraviolet Rays ◽  
Protection Factor ◽  
Ultraviolet Protection Factor ◽  
Fabric Density ◽  
Weave Fabric ◽  
Ultraviolet Protection

In thisstudy, the effect of fabric density and different colors (black and red) on ultraviolet protection factor of woven fabric investigated. The fabric of different composition (100% cotton, 60/40 CVC), two color (black, red) and various density (Ends per inch, Picks per inch) collected. Then UPF rating was measured by spectrophotometer in vitro method. Experimental result showed that higher the fabric density and weight; higher the protection from ultraviolet rays. Besides, it also revealed that black fabric has more UV protection ability than the red one. Another finding of this study is that polyester content increases the UPF value.

scholarly journals Highly Bendable and Durable Waterproof Paper for Ultra-High Electromagnetic Interference Shielding

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1486 ◽  
Author(s):  
Fang Ren ◽  
Han Guo ◽  
Zheng-Zheng Guo ◽  
Yan-Ling Jin ◽  
Hong-Ji Duan ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Silver Nanowires ◽  
Cellulose Fiber ◽  
Dip Coating ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Multiple Reflections ◽  
Water Contact ◽  
Practical Applications ◽  
Emi Se

An efficient electromagnetic interference (EMI) shielding paper with excellent water repellency and mechanical flexibility has been developed, by assembling silver nanowires (AgNWs) and hydrophobic inorganic ceramic on the cellulose paper, via a facile dip-coating preparation. Scanning electron microscope (SEM) observations confirmed that AgNWs were interconnected and densely coated on both sides of the cellulose fiber, which endows the as-prepared paper with high conductivity (33.69 S/cm in-plane direction) at a low AgNW area density of 0.13 mg/cm2. Owing to multiple reflections and scattering between the two outer highly conductive surfaces, the obtained composite presented a high EMI shielding effectiveness (EMI SE) of up to 46 dB against the X band, and ultrahigh specific EMI SE of 271.2 dB mm–1. Moreover, the prepared hydrophobic AgNW/cellulose (H-AgNW/cellulose) composite paper could also maintain high EMI SE and extraordinary waterproofness (water contact angle > 140°) by suffering dozens of bending tests or one thousand peeling tests. Overall, such a multifunctional paper might have practical applications in packaging conductive components and can be used as EMI shielding elements in advanced application areas, even under harsh conditions.

scholarly journals Effect of Textile-Substrate Pore Size on Electromagnetic Interference Shielding Performance of Conductive Nanocomposite Coated Fabrics

2021 ◽  
Author(s):  
Yijie Hou ◽  
Min Guo ◽  
Xiangpeng Li ◽  
Minghan Duan ◽  
Yongtang Jia ◽  
...  
Keyword(s):  
Pore Size ◽  
Electromagnetic Interference ◽  
High Efficiency ◽  
Great Promise ◽  
Shielding Effectiveness ◽  
Emi Shielding ◽  
Emi Shielding Effectiveness ◽  
Fabric Density ◽  
Fabric Structure ◽  
Coated Fabrics

Abstract Textile-substrate electromagnetic interference (EMI) shielding materials show great promise for next-generation electronic communication technology challenges. However, new strategies based on structure optimization are desired for improving EMI shielding performance. Here, we demonstrate the controlling effect of fabric structure on the shielding effectiveness of the EMI fabrics. Plain fabrics with different fabric densities were weaved and used as the substrate to be layer-by-layer assembled by graphite oxide (GO) and polypyrrole (PPy). The conductive GO/PPy nanocomposite coating endows commercial cotton fabrics with an EMI shielding ability. In comparison, the EMI shielding effectiveness of the GO/PPy fabrics is depended on the fabric density, that is, the pore size. The EMI shielding effectiveness of the 100 × 100 picks/ 10cm coated fabric was 19.2 dB in 3.9−6.0 GHz frequency range, which is increased by about 71% through the control of the textile-substrate pore size. Interestingly, the EMI shielding effectiveness always peaks at the fabric density of 100 × 100 picks/ 10cm, different from the electrical conductivity. Moreover, the sueding treatment can further improve the EMI shielding effectiveness of the GO/PPy coated fabrics. It is because that the creation of plush increases the multi-reflection of electromagnetic waves in the fabric. This work presents the significance of fabric structure to EMI shielding performance, offering new opportunities for the development of high efficiency EMI shielding fabrics.

Development and characterization of three-dimensional woven fabric for ultra violet protection

2018 ◽  
Vol 30 (4) ◽  
pp. 536-547
Author(s):  
Adeela Nasreen ◽  
Muhammad Umair ◽  
Khubab Shaker ◽  
Syed Talha Ali Hamdani ◽  
Yasir Nawab
Keyword(s):  
3D Structure ◽  
Three Dimensional ◽  
Air Permeability ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Protection Factor ◽  
Content Type ◽  
Ultraviolet Protection Factor ◽  
Ultraviolet Protection

Purpose The purpose of this paper is to investigate the effect of materials, three dimensional (3D) structure and number of fabric layers on ultraviolet protection factor (UPF), air permeability and thickness of fabrics. Design/methodology/approach Total 24 fabrics samples were developed using two 3D structures and two weft materials. In warp direction cotton (CT) yarn and in weft direction polypropylene (PP) and polyester (PET) were used. Air permeability, thickness and UPF testings were performed and relationship among fabric layers, air permeability, thickness and UPF was developed. Findings UPF and thickness of fabrics increases with number of fabric layers, whereas air permeability decreases with the increase in number of fabric layers. Furthermore, change of multilayer structure from angle interlock to orthogonal interlock having same base weave does not give significant effect on UPF. However, change of material from polyester (PET) to polypropylene (PP) has a dominant effect on UPF. Minimum of three layers of cotton/polyester fabric, without any aid of ultraviolet radiation (UV) resistant coating, are required to achieve good. Cotton/polyester fabrics are more appropriate for outdoor application due to their long-term resistance with sunlight exposure. Originality/value Long-term exposure to UV is detrimental. So, there is need of proper selection of material and fabric to achieve ultraviolet protection. 3D fabrics have yarns in X, Y as well as in Z directions which provide better ultraviolet protection as compared to two dimensional (2D) fabrics. In literature, mostly work was done on ultraviolet protection of 2D fabrics and surface coating of fabrics. There is limited work found on UPF of 3D woven fabrics.

Progress in Advanced Materials Used in Electromagnetic Interference Shielding for Space Applications

2021 ◽  
pp. 530-553
Author(s):  
Rafael Vargas-Bernal ◽  
Bárbara Bermúdez-Reyes ◽  
Margarita Tecpoyotl-Torres
Keyword(s):  
Electromagnetic Interference ◽  
Electromagnetic Waves ◽  
Space Station ◽  
Advanced Materials ◽  
Shielding Effectiveness ◽  
Space Applications ◽  
Electrical And Magnetic Properties ◽  
Aerospace Applications ◽  
Technical Requirements ◽  
Materials Used

Aerospace applications experience electromagnetic interference produced by the space environment and by the materials, devices, and systems used in satellites, space shuttles, the international space station, and airplanes. The advanced materials represent a technological possibility to develop coatings that are able to offer a better shielding effectiveness against electromagnetic interference due to the possibility of controlling its electrical and magnetic properties as well as to that the size of the materials is very similar to the electromagnetic waves that it receives. In this chapter, an analysis of progress over advanced materials is presented with the aim of diffusing the role that nanomaterials have had, have and will have to increase the shielding to electromagnetic interference. Nanomaterials will protect aerospace components in the range of Hz to THz, but the huge advantage is that the range of protection can be optimized according to the technical requirements with a considerable weight reduction.

scholarly journals Multifunctional Chitosan/Gold Nanoparticles Coatings for Biomedical Textiles

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1064 ◽  
Author(s):  
Silva ◽  
Ladchumananandasivam ◽  
Nascimento ◽  
Silva ◽  
Oliveira ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Uv Light ◽  
Antimicrobial Effect ◽  
Radiation Shielding ◽  
Protection Factor ◽  
Ultraviolet Protection Factor ◽  
Chitosan Matrix ◽  
Coated Fabrics ◽  
Average Size

Gold nanoparticles (AuNPs), chemically synthesized by citrate reduction, were for the first time immobilized onto chitosan-treated soybean knitted fabric via exhaustion method. AuNPs were successfully produced in the form of highly spherical, moderated polydisperse, stable structures. Their average size was estimated at ≈35 nm. Successful immobilization of chitosan and AuNPs were confirmed by alterations in the fabric’s spectrophotometric reflectance spectrum and by detection of nitrogen and gold, non-conjugated C=O stretching vibrations of carbonyl functional groups and residual N-acetyl groups characteristic bands by X-ray photoelectron spectroscopy (XPS) and Fourier-Transform Infrared Spectroscopy (FTIR) analysis. XPS analysis confirms the strong binding of AuNPs on the chitosan matrix. The fabrics’ thermal stability increased with the introduction of both chitosan and AuNPs. Coated fabrics revealed an ultraviolet protection factor (UPF) of +50, which established their effectiveness in ultraviolet (UV) radiation shielding. They were also found to resist up to 5 washing cycles with low loss of immobilized AuNPs. Compared with AuNPs or chitosan alone, the combined functionalized coating on soy fabrics demonstrated an improved antimicrobial effect by reducing Staphylococcus aureus adhesion (99.94%) and Escherichia coli (96.26%). Overall, the engineered fabrics were confirmed as multifunctional, displaying attractive optical properties, UV-light protection and important antimicrobial features, that increase their interest for potential biomedical applications.

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