scholarly journals Epsilon-negative media from the viewpoint of materials science

2021 ◽  
Vol 8 ◽  
pp. 11
Author(s):  
Guohua Fan ◽  
Kai Sun ◽  
Qing Hou ◽  
Zhongyang Wang ◽  
Yao Liu ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Materials Science ◽  
Functional Materials ◽  
Negative Permittivity ◽  
Electromagnetic Interference Shielding ◽  
Comprehensive Review ◽  
Potential Applications ◽  
Negative Materials ◽  
The Relationship ◽  
Negative Property

A comprehensive review of the fundamentals and applications of epsilon-negative materials is presented in this paper. Percolative composites, as well as homogeneous ceramics or polymers, have been investigated to obtain the tailorable epsilon-negative properties. It's confirmed the anomalous epsilon-negative property can be realized in conventional materials. Meanwhile, from the perspective of materials science, the relationship between the negative permittivity and the composition and microstructure of materials has been clarified. It's demonstrated that the epsilon-negative performance is attributed to the plasmonic response of delocalized electrons within the materials and can be modulated by it. Moreover, the potential applications of epsilon-negative materials in electromagnetic interference shielding, laminated composites for multilayered capacitance, coil-less electric inductors, and epsilon-near-zero metamaterials are reviewed. The development of epsilon-negative materials has enriched the connotation of metamaterials and advanced functional materials, and has accelerated the integration of metamaterials and natural materials.

Multi-interfaced graphene aerogel/polydimethylsiloxane metacomposites with tunable electrical conductivity for enhanced electromagnetic interference shielding

2020 ◽  
Vol 8 (34) ◽  
pp. 11748-11759 ◽  
Author(s):  
Jingnan Ni ◽  
Ruoyu Zhan ◽  
Jun Qiu ◽  
Jincheng Fan ◽  
Binbin Dong ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Microwave Absorption ◽  
Electromagnetic Interference ◽  
Three Dimensional ◽  
Interface Structure ◽  
Negative Permittivity ◽  
Electromagnetic Interference Shielding ◽  
Graphene Aerogel

Three-dimensional graphene aerogel/polydimethylsiloxane metacomposites with an integral multi-interface structure possess adjustable negative permittivity, excellent microwave absorption and electromagnetic interference shielding.

Effect of fiber length and blending method on the tensile properties of ring spun chitosan–cotton blend yarns

2016 ◽  
Vol 87 (2) ◽  
pp. 244-257 ◽  
Author(s):  
Ngan Yi Kitty Lam ◽  
Meng Zhang ◽  
Hui-fen Guo ◽  
Chu Po Ho ◽  
Li Li
Keyword(s):  
Tensile Properties ◽  
Textile Industry ◽  
Fiber Length ◽  
Production Cost ◽  
Materials Science ◽  
Rapid Development ◽  
Blending Method ◽  
Potential Applications ◽  
Chitosan Fiber ◽  
The Relationship

Chitosan has been widely studied for use in many areas, such as for its applications in the biomedical, engineering and pharmaceutical fields, as well as in industry, because of its unique properties, including biodegradability, antimicrobial activity, polycationic nature and biocompatibility. Thanks to the rapid development of materials science, chitosan applications are now possible in textiles. However, there are still many limitations of chitosan fibers in terms of their high electrostaticity, poor mechanical properties and high cost, which are obstacles that inhibit potential applications of chitosan fiber in the industry. Generally, in order to achieve the best performance with chitosan and enhance its commercial value, chitosan fibers are usually blended with long cotton fibers in the textile industry. Therefore, based on preliminary experiments and feedback from the industry, this study was carried out to further investigate the relationship between fiber length, fiber interaction and yarn performance. The results of this study would therefore help to reduce the production cost of yarns with the blending parameters used and also expand the utilization and applications beyond medical applications to fashion-based functional wear. The sliver-blending method offers better tensile properties of yarn samples, while the fiber-blending method offers higher uniformity of fiber distribution. This study would help to reduce the production cost of yarns by blending and also to expand the utilization and application not limited to fashion-based functional wear.

scholarly journals Preparation and Study of Electromagnetic Interference Shielding Materials Comprised of Ni-Co Coated on Web-Like Biocarbon Nanofibers via Electroless Deposition

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Xiaohu Huang ◽  
Bo Dai ◽  
Yong Ren ◽  
Jing Xu ◽  
Pei Zhu
Keyword(s):  
Electromagnetic Interference ◽  
Electroless Deposition ◽  
Paraffin Wax ◽  
Matrix Composites ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Electrical Conductivities ◽  
Potential Applications ◽  
Emi Se ◽  
Factor Governing

Electromagnetic interference (EMI) shielding materials made of Ni-Co coated on web-like biocarbon nanofibers were successfully prepared by electroless plating. Biocarbon nanofibers (CF) with a novel web-like structure comprised of entangled and interconnected carbon nanoribbons were obtained using bacterial cellulose pyrolyzed at 1200°C. Paraffin wax matrix composites filled with different loadings (10, 20, and 30 wt%, resp.) of CF and Ni-Co coated CF (NCCF) were prepared. The electrical conductivities and electromagnetic parameters of the composites were investigated by the four-probe method and vector network analysis. From these results, the EMI shielding efficiencies (SE) of NCCF composites were shown to be significantly higher than that of CF at the same mass fraction. The paraffin wax composites containing 30 wt% NCCF showed the highest EMI SE of 41.2 dB (99.99% attenuation), which are attributed to the higher electrical conductivity and permittivity of the NCCF composites than the CF composites. Additionally, EMI SE increased with an increase in CF and NCCF loading and the absorption was determined to be the primary factor governing EMI shielding. This study conclusively reveals that NCCF composites have potential applications as EMI shielding materials.

scholarly journals Single-molecule force spectroscopy: A facile technique for studying the interactions between biomolecules and materials interfaces

2020 ◽  
Vol 39 (1) ◽  
pp. 116-129
Author(s):  
Li Wang ◽  
Yuhong Qian ◽  
Yantao Sun ◽  
Bin Liu ◽  
Gang Wei
Keyword(s):  
Single Molecule ◽  
Materials Science ◽  
Force Spectroscopy ◽  
Functional Materials ◽  
Dynamic Force ◽  
Single Molecule Force Spectroscopy ◽  
Design And Synthesis ◽  
Atomic Force ◽  
Potential Applications ◽  
Force Mapping

AbstractThe quantification of the interactions between biomolecules and materials interfaces is crucial for design and synthesis functional hybrid bionanomaterials for materials science, nanotechnology, biosensor, biomedicine, tissue engineering, and other applications. Atomic force spectroscopy (AFM)-based single-molecule force spectroscopy (SMFS) provides a direct way for measuring the binding and unbinding forces between various biomolecules (such as DNA, protein, peptide, antibody, antigen, and others) and different materials interfaces. Therefore, in this review, we summarize the advance of SMFS technique for studying the interactions between biomolecules and materials interfaces. To achieve this aim, firstly we introduce the methods for the functionalization of AFM tip and the preparation of functional materials interfaces, as well as typical operation modes of SMFS including dynamic force spectroscopy, force mapping, and force clamping. Then, typical cases of SMFS for studying the interactions of various biomolecules with materials interfaces are presented in detail. In addition, potential applications of the SMFS-based determination of the biomolecule-materials interactions for biosensors, DNA based mis-match, and calculation of binding free energies are also demonstrated and discussed. We believe this work will provide preliminary but important information for readers to understand the principles of SMFS experiments, and at the same time, inspire the utilization of SMFS technique for studying the intermolecular, intramolecular, and molecule-material interactions, which will be valuable to promote the reasonable design of biomolecule-based hybrid nanomaterials.

scholarly journals Polyethylene Composites with Segregated Carbon Nanotubes Network: Low Frequency Plasmons and High Electromagnetic Interference Shielding Efficiency

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1118 ◽  
Author(s):  
Ludmila Vovchenko ◽  
Ludmila Matzui ◽  
Viktor Oliynyk ◽  
Yurii Milovanov ◽  
Yevgen Mamunya ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electromagnetic Interference ◽  
Complex Impedance ◽  
Low Frequency ◽  
Negative Permittivity ◽  
Network Interface ◽  
60 Ghz ◽  
Frequency Range ◽  
Electromagnetic Interference Shielding ◽  
Thick Sample

Polyethylene (PE) based composites with segregated carbon nanotubes (CNTs) network was successfully prepared by hot compressing of a mechanical mixture of PE and CNT powders. Through comparison with a composite comprising randomly distributed carbon nanotubes of the same concentration, we prove that namely the segregated CNT network is responsible for the excellent electrical properties, i.e., 10−1 S/m at 0.5–1% and 10 S/m at 6–12% of CNT. The investigation of the complex impedance in the frequency range 1 kHz–2 MHz shows that the sign of real part of the dielectric permittivity ε r ′ changes from positive to negative in electrically percolated composites indicating metal-like behavior of CNT segregated network. The obtained negative permittivity and AC conductivity behavior versus frequency for high CNT content (3–12%) are described by the Drude model. At the same time, in contrast to reflective metals, high electromagnetic shielding efficiency of fabricated PE composites in the frequency range 40–60 GHz, i.e., close to 100% at 1 mm thick sample, was due to absorption coursed by multiple reflection on every PE-CNT segregated network interface followed by electromagnetic radiation absorbed in each isolated PE granule surrounded by conductive CNT shells.

scholarly journals Light-Weight Multi-Walled Carbon Nanotube Buckypaper/Glass Fiber-Epoxy Composites for Strong Electromagnetic Interference Shielding and Efficient Microwave Absorption

2021 ◽  
Author(s):  
Bruno Ribeiro ◽  
Newton Adriano Gomes ◽  
Mirabel Cerqueira Rezende
Keyword(s):  
Carbon Nanotube ◽  
Glass Fiber ◽  
Electromagnetic Interference ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Multi Walled Carbon Nanotube ◽  
X Band ◽  
Potential Applications ◽  
Emi Se ◽  
Minimum Reflection Loss

Abstract Multi-walled carbon nanotube buckypaper (BP) reinforced glass fiber-epoxy (GF/EP) composites were selected to fabricate electromagnetic interference (EMI) shielding and microwave absorbing composites. Six different composite configurations with 3.0 mm thick have been conceived and tested over the X-band (8.2-12.4 GHz). Flexible and low density (0.29 g/cm3) BP provided a high specific EMI SE of 55 dB with controlled electrical conductivity. GF/EP/BP111 and GF/EP/BP101 composites possess EMI SE as high as of 50-60 dB, which can be attributed to the number of BP inserted and variation in the wave-transmitting layer of the laminates. Furthermore, the shielding mechanism was discussed, and it suggested that the dominant contribution to EMI SE was absorption. GF/EP/BP110 laminate demonstrated suitable EMI performance (~20 dB) and excellent microwave performance, achieving an effective -10 dB bandwidth of 3.04 GHz and minimum reflection loss (RL) value of -21.16 dB at 10.37 GHz. On the basis of these results, GF/EP/BP composites prepared in this work have potential applications as both EMI shielding and microwave absorber materials given their facile preparation and lightweight use.

Hydrocephalus in Spinal Muscular Atrophy: A Case Report and Review of the Literature

2020 ◽  
Author(s):  
Jeetendra P. Sah ◽  
Aaron W. Abrams ◽  
Geetha Chari ◽  
Craig Linden ◽  
Yaacov Anziska
Keyword(s):  
Spinal Muscular Atrophy ◽  
Clinical Characteristics ◽  
Clinical Presentation ◽  
Muscular Atrophy ◽  
Communicating Hydrocephalus ◽  
Type I ◽  
Review Of The Literature ◽  
Radiographic Findings ◽  
Comprehensive Review ◽  
The Relationship

AbstractIn this article, we reported a case of spinal muscular atrophy (SMA) type I noted to have tetraventricular hydrocephalus with Blake's pouch cyst at 8 months of age following intrathecal nusinersen therapy. The association of hydrocephalus with SMA is rarely reported in the literature. Development of hydrocephalus after intrathecal nusinersen therapy is also reported in some cases, but a cause–effect relationship is not yet established. The aim of this study was to describe the clinical characteristics of a patient with SMA type I and hydrocephalus, to review similar cases reported in the literature, and to explore the relationship between nusinersen therapy and development of hydrocephalus. The clinical presentation and radiographic findings of the patient are described and a comprehensive review of the literature was conducted. The adverse effect of communicating hydrocephalus related to nusinersen therapy is being reported and the authors suggest carefully monitoring for features of hydrocephalus developing during the course of nusinersen therapy.

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