Core–Shell Chain-Like Cu@Ni Composite with Dual Absorption Peaks to Improve Microwave Absorption Properties

NANO ◽  
2018 ◽  
Vol 13 (05) ◽  
pp. 1850052
Author(s):  
Yuanyuan Zhou ◽  
Jianying Deng ◽  
Shimei Li ◽  
Zefeng Li
Keyword(s):  
Hydrothermal Reaction ◽  
Low Cost ◽  
Electromagnetic Properties ◽  
Formation Mechanisms ◽  
Core Shell ◽  
The Novel ◽  
Redox Potentials ◽  
X Ray Diffraction ◽  
Ni Alloy ◽  
Absorbing Material

Core–shell Cu@Ni chains were successfully synthesized through a mild hydrothermal reaction. The morphology, structure and microwave electromagnetic properties of the composite were then characterized by X-ray diffraction, energy-dispersive spectroscopy, scanning electron microscopy and vector network analysis. The formation mechanisms of the core–shell structure and one-dimensional chains were ascribed to the varying redox potentials of Cu and Ni ions and the magnetic dipole–dipole attraction. Furthermore, a minimal reflection loss (RL) of [Formula: see text]20.7[Formula: see text]dB was observed at 9.6[Formula: see text]GHz with a thickness of 2.0[Formula: see text]mm and the effective absorption ([Formula: see text]10[Formula: see text]dB, 90% microwave attenuation) bandwidth can be adjusted between 5.2[Formula: see text]GHz and 16.6[Formula: see text]GHz for the thin absorber thickness of 2.0–4.0[Formula: see text]mm. The novel core–shell chain-like Cu@Ni alloy can be used as a promising absorbing material because it shows numerous features such as thin thickness, strong absorption, low cost and lightweight.

scholarly journals Calcium Hydroxyapatite-Based Marine Origin: Novel Sunscreen Materials for Cosmeceutical Treatments

2018 ◽  
Vol 34 (6) ◽  
pp. 2770-2776
Author(s):  
Mohd Zul Helmi Rozaini ◽  
Habibah Hamzah ◽  
Chia Poh Wai ◽  
Mohd Hasmizam Razali ◽  
Uwaisulqarni M. Osman ◽  
...  
Keyword(s):  
Uv Light ◽  
Low Cost ◽  
Value Added ◽  
Dry Weight ◽  
Calcium Hydroxyapatite ◽  
The Novel ◽  
X Ray Diffraction ◽  
Light Absorber ◽  
Mn Doped ◽  
Value Added Products

Fringescalesardinella or TambanSisik bones have been discovered can be utilized as sunscreen agent in cosmeceuticals. Its flesh is the main ingredient in keropoklekor or fish crackers in Malaysia and the bones contained very high hydroxyapatite (HAp), (Ca10(PO4)6(OH)2) compound which exhibit as UV light absorber. The percentage yields obtained from the hydrothermal extraction consist of 41.2 ± 0.66 % (w/w) of HApwhich was almost half of the dry weight of 100 g samples.The additional of manganeseand ferum,initiated the novel sunscreen materials from hydroxyapatite-Fe and hydroxyapatite-Mn doped (modified bones). The unmodified HAp recorded with SPF 20 and modified HAp-Mn measured with SPF 40. Modified HAp-Fe emulsions were recorded with SPF 50 as the highest SPF value. Therefore, the bones have been characterized using Fourier Transform Infrared Radiation (FTIR)spectroscopy and x-Ray diffraction (XRD).The results obtained clearly indicated that the HAp existence in waste of Fringescalesardinella bones with addition of FeCl2which exhibits high potential as sunscreen compared to manganese and unmodified bones. Thus, the utilization of waste from the fish bones not only produce value-added products from low-cost resources, but also help in reducing pollution to the environment and preserved the global sustainability.

Novel Phase Transformation Phenomenon of Potassium Teteratitanate Nanofibres Synthesized from H2TiO3

2010 ◽  
Vol 177 ◽  
pp. 62-65
Author(s):  
Na Zhang ◽  
Hai Fang Xu ◽  
Yu Lin Li ◽  
Qiang Li ◽  
Cheng Zhang
Keyword(s):  
Phase Transformation ◽  
Hydrothermal Reaction ◽  
Anatase Tio2 ◽  
The Novel ◽  
X Ray Diffraction ◽  
Rutile Tio2 ◽  
X Ray ◽  
Tio2 Particles ◽  
Change Behavior ◽  
In Series

Starting from H2TiO3, potassium teteratitanate (K2Ti4O9) nanofibres with the length of several micrometers and the diameter of 100nm were directly synthesized by solid state reaction. The novel phase transformation and structure change behavior was investigated by the X-ray diffraction technique (XRD), scanning electron microscopy (SEM) in details. In series of hydrothermal reaction, the K2Ti4O9 could transfer to anatase TiO2 and rutile TiO2. Aggregated anatase TiO2 particles and rod-like rutile TiO2 were produced respectively in 1M HCl solutions at 1600C and 2200C. When the 0.01M HCl solution was considered as solvent, the mixture of floral anatase TiO2 and K2Ti4O9 were present together.

Facile Controlled Synthesis of Manganese Oxide Hierarchical Microspheres by Hydrothermal Method

2011 ◽  
Vol 688 ◽  
pp. 107-115 ◽  
Author(s):  
Dong Yan Li ◽  
Yun Fa Chen
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Reaction ◽  
Nitrogen Adsorption ◽  
Bet Surface Area ◽  
Formation Mechanisms ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Hydrothermal Temperature ◽  
Transmission Electron ◽  
Hierarchical Microspheres

MnO2hierarchical microsphere has been synthesized by a facile and direct hydrothermal reaction between KMnO4and HCl without the aids of catalysts, surfactants or templates. The as-prepared microsphere, as characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) analysis and nitrogen adsorption and desorption, is in form of K0.27MnO2(H2O )0.54, with a flower-like hierarchical microsphere structure and a BET surface area value of 52 m2/g. The morphology of the product can be simply tailed by controlled by reaction temperature or period and crystallinity can be modified by changing the concentrate of KMnO4. In general, excessive KMnO4and low hydrothermal temperature are favor to forming flower-like hierarchical structure. Besides, the formation mechanisms of the hierarchical schemes are proposed.

High-Jc YBCO coatings on reel-to-reel dip-coated Gd2O3 seed buffer layers epitaxially fabricated on biaxially textured Ni and Ni-(3at%W-1.7at%Fe) alloy tapes

2001 ◽  
Vol 689 ◽  
Author(s):  
Tolga Aytug ◽  
M. Paranthaman ◽  
S. Sathyamurthy ◽  
B. W. Kang ◽  
D. B. Beach ◽  
...  
Keyword(s):  
Low Cost ◽  
Dip Coating ◽  
Buffer Layers ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Ybco Films ◽  
Ni Alloy ◽  
Current Densities ◽  
Alloy Metal

ABSTRACTA low-cost, non-vacuum reel-to reel dip-coating system has been used to continuously fabricate epitaxial Gd2O3 buffer layers on mechanically strengthened, biaxially textured Ni- (3at.%W-1.7at%Fe), defined as Ni-alloy, metal tapes. X-ray diffraction analysis of the seed Gd2O3 layers indicated that well textured films can be obtained at processing temperatures (Tp) between 1100 and 1175°C. Processing speed did not significantly affect the crystalline quality of the Gd2O3. Scanning electron microscopy revealed a continuous, dense and crack-free surface morphology for these dip-coated buffers. The Gd2O3 layer thickness led to remarkable differences in the growth characteristics of the subsequent YSZ and CeO2 layers deposited by rfmagnetron sputtering. Epitaxial YBCO films grown by pulsed laser deposition on the short prototype CeO2/YSZ/Gd2O3/Ni-(3at%W-1.7at%Fe) conductors yielded self-field critical current densities (Jc) as high as 1.2×106 A/cm2 at 77 K. Pure Ni tapes were used to asses the viability of dip-coated buffers for long length coated conductor fabrication. The YBCO films, grown on 80 cm long and 1 cm wide CeO2/YSZ/Gd2O3 buffered Ni tapes by the industrially scalable ex-situ BaF2 precursor process, exhibited end-to-end self-field Jc of 6.25×105 A/cm2 at 77 K.

Core-Shell Structured Nanocomposites with Electromagnetic Properties

2013 ◽  
Vol 785-786 ◽  
pp. 607-612
Author(s):  
Xi Chang Wang ◽  
Xin Li
Keyword(s):  
Magnetic Particles ◽  
Oxidative Polymerization ◽  
Conductive Polymer ◽  
Electromagnetic Properties ◽  
Molar Ratio ◽  
Core Shell ◽  
X Ray Diffraction ◽  
The Core ◽  
Transmission Electron ◽  
Polymer Shells

The electromagnetic nanocomposites with a core-shell structure are synthesized by in situ chemical oxidative polymerization. The Co doped Fe3O4magnetic particles (Co-Fe3O4) act as the core and poly (3,4-ethylenedioxythiophene)-poly (sodium-p-styrenesulfonate) (PEDOT-PSS) as the conductive polymer shells. The morphology, structure, crystallinity, conductive and magnetic properties were studied by transmission electron microscopy (TEM), Scanning electron Microscope (SEM), Fourier Transform Infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD), four-probe conductivity meter and vibrating sample magnetometer (VSM). It is found that the core-shell nanocomposites exhibit controllable electromagnetic properties by adjusting the molar ratio of Co-Fe3O4to EDOT monomer.

Fabrication and characterization of spinel Ni0.5Cu0.5Co2O4 nanoparticles as bi-functional catalysts for oxygen reduction and evolution reaction

2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940060
Author(s):  
Jin Xiao ◽  
Lin Zhang ◽  
Jiabin Peng ◽  
Haitong Xue ◽  
Hongchun Yuan ◽  
...  
Keyword(s):  
Transition Metal Oxides ◽  
Hydrothermal Reaction ◽  
Low Cost ◽  
Rotating Disk ◽  
Rotating Disk Electrode ◽  
X Ray Diffraction ◽  
Catalytic Activities ◽  
Energy Applications ◽  
Electrode Technique

Developing efficient and low-cost bi-functional electrolytes for energy applications such as fuel cells and rechargeable metal-air batteries is highly desirable. Here, we have synthesized spinel Ni[Formula: see text]Cu[Formula: see text]Co2O4 (NCC) nanoparticles as nonprecious bi-functional electrocatalysts by a simple hydrothermal reaction method. The phase structure and the morphology of NCC nanoparticles have been investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) while the electrocatalytic activity of the samples has been studied in alkaline solution by using rotating disk electrode technique. The electrocatalysts have showed a comparable ORR and OER catalytic activities compared with of those of the other transition metal oxides, suggesting the feasibility of the NCC as the bi-functional electrolytes materials for ORR and OER.

SiO2-Coated Fe-Ni Alloy Core–Shell Structures Synthesized by a Facile Chemical Method

2016 ◽  
Vol 697 ◽  
pp. 303-306
Author(s):  
Guo Jun Li ◽  
Yun Hui Mei ◽  
Feng Hou
Keyword(s):  
Magnetic Properties ◽  
Spherical Particles ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
Alloy Particles ◽  
Transmission Electron ◽  
Ni Alloy ◽  
Wet Chemical ◽  
Silica Layers

Fe-Ni@ SiO2core–shell structured micrometer spherical particles with nanometer thick SiO2 shell were fabricated by a facile wet chemical process, their compositions and mechanisms were investigated using x-ray diffraction and Fourier transform of infra-red spectra, and their microstructures and magnetic properties were analyzed by high-resolution transmission electron microscopy and vibrating sample magnetometer. The structure of the synthesized SiO2-coated Fe-Ni alloy particles varied with adding TEOS contents. As-prepared Fe-Ni@SiO2 composites exhibit typical soft magnetic properties. Their highest saturation magnetization approximately linear decreases from 176 emu g−1for pure Fe-Ni alloy powders to 121 emu g−1for the coated powders with 20nm amorphous silica layers, but the coercivity of all different thickness SiO2-coated Fe-Ni alloy powders maintains in the range of about 25 Oe.

Synthesis and Magnetic Properties of Fe–Ni Alloy Nanoparticles Obtained by Hydrothermal Reaction

2011 ◽  
Vol 239-242 ◽  
pp. 748-753 ◽  
Author(s):  
Ming Liang Yuan ◽  
Jia Hua Tao ◽  
Liang Yu ◽  
Cong Song ◽  
Guan Zhou Qiu ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Hydrothermal Reaction ◽  
Low Cost ◽  
Particle Morphology ◽  
Alkaline Media ◽  
Alloy Nanoparticles ◽  
Important Relationship ◽  
Structure Morphology ◽  
Ni Alloy

The magnetic properties of Fe-Ni alloy nanoparticles with particle size in the range 35-45 nm were prepared by almost simultaneously reducing Fe(II) and Ni(II) solution using hydrazine hydrate as a reducing agent in strong alkaline media for two hours at 80 °C. Chemical composition, crystal structure, morphology, thermal stability and magnetic properties of as synthesized Fe-Ni alloy nanoparticles were systematically characterized by means of XRD, TEM, TG-DSC and VSM. These results indicate that there is a vitally important relationship among particle size, particle morphology, and different mol ratio of FeSO4to NiSO4. The saturation magnetization (Ms). and coercivity (Hc) strongly affected by the composition of Fe-Ni alloy nanoparticles. The hydrothermal reaction is a simple, effective, and low-cost synthetic method to prepare FeNi3alloy nanoparticles.

Mechanical, electrical, and electromagnetic properties of hybrid graphene/glass fiber/epoxy composite

2019 ◽  
Vol 27 (5) ◽  
pp. 262-267 ◽  
Author(s):  
Kamila Kunrath ◽  
Eduardo Fischer Kerche ◽  
Mirabel Cerqueira Rezende ◽  
Sandro Campos Amico
Keyword(s):  
Electrical Conductivity ◽  
Glass Fiber ◽  
Epoxy Composite ◽  
Low Cost ◽  
Electromagnetic Properties ◽  
Radar Absorbing Material ◽  
Flexural Testing ◽  
Low Concentrations ◽  
Absorbing Material ◽  
Graphene Glass

This study presents the development of a novel three-component composite based on glass fiber/epoxy resin/graphene nanoplatelets (GNPs) aiming to obtain radar absorbing material (RAM). The composite was produced by vacuum-assisted resin transfer molding and characterized under tensile and flexural testing, reflectivity, and electrical conductivity analyses. The mechanical properties were not significantly affected by the incorporation of GNP nanofiller. However, electrical conductivity of the three-component composites increased sharply and the percolation threshold was reached with around 3 wt% GNP (surface conductivity) and 4 wt% GNP (volumetric conductivity). Furthermore, reflectivity showed excellent attenuation (up to 99.99%) in the 8.2–12.4 GHz frequency range. These attenuation levels were obtained even at low concentrations (0.1 wt%) of GNP nanofiller, indicating the possibility of producing composites with low cost and easy processing for advanced applications as RAMs.

Ten-Vertex Polyhedral Monocarbaborane Chemistry. The Novel High-Yield Formation of the Ten-Vertex closo Compound [6-(PMe2Ph)-closo-1-CB9H9] from the Thermolysis of [8,8-(PMe2Ph)2-nido-8,7-PtCB9H11]

1993 ◽  
Vol 58 (12) ◽  
pp. 2924-2935 ◽  
Author(s):  
Jane H. Jones ◽  
Bohumil Štíbr ◽  
John D. Kennedy ◽  
Mark Thornton-Pett
Keyword(s):  
Nmr Spectroscopy ◽  
Diffraction Analysis ◽  
High Yield ◽  
Monoclinic Space Group ◽  
The Novel ◽  
X Ray Diffraction ◽  
Metal Centre ◽  
X Ray ◽  
Yield Formation ◽  
Boiling Toluene

Thermolysis of [8,8-(PMe2Ph)2-nido-8,7-PtCB9H11] in boiling toluene solution results in an elimination of the platinum centre and cluster closure to give the ten-vertex closo species [6-(PMe2Ph)-closo-1-CB9H9] in 85% yield as a colourles air stable solid. The product is characterized by NMR spectroscopy and single-crystal X-ray diffraction analysis. Crystals (from hexane-dichloromethane) are monoclinic, space group P21/c, with a = 903.20(9), b = 1 481.86(11), c = 2 320.0(2) pm, β = 97.860(7)° and Z = 8, and the structure has been refined to R(Rw) = 0.045(0.051) for 3 281 observed reflections with Fo > 2.0σ(Fo). The clean high-yield elimination of a metal centre from a polyhedral metallaborane or metallaheteroborane species is very rare.

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