SOLID STATE SCIENCES
·
2024
·
IF 3.4
Liming Zhu,Dezhu Sun,Xuyang Li,Wei Liu,Jiaqiang Huang,Caihang Liang,Xiaokai Hu
Bismuth telluride and lead telluride are typical thermoelectric semiconductors that are metallized for electrical contacts before being assembled into devices. In this study, three iron-group metals of nickel cobalt iron, were chemically plated on n-type bismuth telluride as the prospective contact material for adhesion and barrier in soldering connection with copper. Aluminum was used as the sacrificial anode to ensure iron deposition. The sensitization in borohydride solution facilitated the subsequent plating of metals. The plating rates were determined by gravimetric method. The crystalline structure and morphology of films were characterized. Electrochemical polarizations were undertaken to compare the driving force among three plating reactions through the reduction of metallic cations and the oxidation of hypophosphite anions with the mixed potential theory. The heterojunction of bismuth telluride with copper was fabricated by reflow soldering with Sn 95 Sb 5 foil, and the interfacial resistivity was evaluated by multiple resistance measurements across the junction.
研究领域:
材料科学
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电化学
·
热电学
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2018
·
IF 6.578
Jianfeng Li,Shujuan Guo,Zhaozan Xu,Jianguo Li,Zihe Pan,Zhiping Du,Fangqin Cheng
In order to reduce the wetting and fouling propensity of polyvinylidene fluoride (PVDF) membrane during coking wastewater treatment by membrane distillation, two kinds of omniphobic PVDF composite membranes were prepared by coating SiO 2 nanoparticles on PVDF membrane surface via electrostatic adsorption or chemical bonding respectively, and subsequently fluorination. The coated SiO 2 nanoparticles observed as amounts of nano-scale protrusions by scanning electron microscope constructed a re-entrant structure and enhanced membrane surface roughness . The omniphobicity of the modified membranes was confirmed by high contact angles (> 150°) for water, diiodomethane and ethylene glycol on the membrane surface. The omniphobic layer with SiO 2 nanoparticles coated via chemical bonding was more stable than electrostatic adsorption. Both the omniphobic PVDF membranes exhibited stable and high rejections of the inorganic and organic contaminants, which were determined by conductivity, total organic carbon and three-dimensional excitation-emission fluorescence spectroscopy of the distillate. The modified omniphobic membranes also showed much less flux decline than the pristine PVDF membrane in direct contact membrane distillation tests (120 h), suggesting their excellent anti-fouling performance. This study indicates that coating silica nanoparticles via chemical bonding is an effective and promising method to fabricate omniphobic PVDF membrane for coking wastewater treatment.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER COMPOSITES
·
2024
·
IF 4.8
Pei Wang,Kai Li,Mingkun Xu,Chaoyong Deng,Lihong Su,Yonggang Guo
To achieve new current collector (pantograph strip, electric brush) with easy industrialization and high strength-toughness, carbon fiber and copper fiber reinforced phenol-formaldehyde (Cu f /C f /PF) composite is fabricated by over-lapping and hot-pressing processes. Cu f /C f /PF composite has compact structure and good interfacial bonding between fibers and resin matrix. Cu f /C f /PF composite is superior to carbon skateboard in terms of electrical conductivity, mechanical strength, and friction behavior. As the carbon fiber content increases, fracture failure mechanism of Cu f /C f /PF composite transforms from plastic failure into brittle fracture. Wear mechanism is studied by combining electrical contacting and sliding friction, and appropriate arc discharge (2.48%) is benefit for the resin-based composite to form a smooth tribolayer, but high arc discharge rate (4.83%) rapidly deteriorates wear condition on the worn surface. Highlights Carbon fiber and copper fiber mixing reinforce resin-based composite. Cu f /C f /PF composite has high strength-toughness and low friction. Fracture failure mode changes to brittle fracture with increasing carbon fiber. Wear mechanism includes electrical contacting and sliding friction. Appropriate arc discharge improve friction performance of resin-based composite.
研究领域:
材料科学
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机械工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
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2022
·Vol. 106
·期 2
·444-454
·
IF 2.606
Zhang Ji,Mu Chengfa,Shen Tao,Qi Gengxin
Different micro-structured SnO 2 powders were synthesized by hydrothermal and chemical co-precipitation methods. The influence of milling process and sintering parameters on the physical properties of Ag/SnO 2 electrical contact materials was investigated. The microstructure and physical properties of Ag/SnO 2 electrical contact materials were characterized by X-ray Diffraction, Scanning Electron Microscopy and Conductivity analyzer. The results showed that spherical SnO 2 (s) powders with a diameter about 2 μm were synthesized. With increased milling time, there was a slight decrease in the average sizes of Ag/SnO 2 (s) powders, but no significant difference. The optimal density of 9.545 g∙cm −3 and resistivity of 2.67 μΩ∙cm of Ag/SnO 2 (s) electrical contact materials were obtained after sintering at 860 °C for 6 h in air atmosphere. The promotion of sintering densification and improvement of physical properties of Ag/SnO 2 (s) contact may be due to the combined effects of mechanical activation energy and higher sintering temperature. Using the finite element method, simulation models were developed to interpret the effects of different micro-structured SnO 2 powders on the physical properties of Ag/SnO 2 materials.
Graphical abstract
研究领域:
材料科学
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电气工程
✓ 已验证
DOI
高影响因子
Jove-Journal of Visualized Experiments
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2013
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IF 0
Mingxia Song,Arnaud Stolz,Douguo Zhang,Juan Arocas,Laurent Markey,Gérard Colas des Francs,Erik Dujardin,Alexandre Bouhelier
Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information support1,2,3. In this context, metal nanowires are especially desirable for realizing dense routing networks4. A prerequisite to operate such shared nanowire-based platform relies on our ability to electrically contact individual metal nanowires and efficiently excite surface plasmon polaritons5 in this information support. In this article, we describe a protocol to bring electrical terminals to chemically-synthesized silver nanowires6 randomly distributed on a glass substrate7. The positions of the nanowire ends with respect to predefined landmarks are precisely located using standard optical transmission microscopy before encapsulation in an electron-sensitive resist. Trenches representing the electrode layout are subsequently designed by electron-beam lithography. Metal electrodes are then fabricated by thermally evaporating a Cr/Au layer followed by a chemical lift-off. The contacted silver nanowires are finally transferred to a leakage radiation microscope for surface plasmon excitation and characterization8,9. Surface plasmons are launched in the nanowires by focusing a near infrared laser beam on a diffraction-limited spot overlapping one nanowire extremity5,9. For sufficiently large nanowires, the surface plasmon mode leaks into the glass substrate9,10. This leakage radiation is readily detected, imaged, and analyzed in the different conjugate planes in leakage radiation microscopy9,11. The electrical terminals do not affect the plasmon propagation. However, a current-induced morphological deterioration of the nanowire drastically degrades the flow of surface plasmons. The combination of surface plasmon leakage radiation microscopy with a simultaneous analysis of the nanowire electrical transport characteristics reveals the intrinsic limitations of such plasmonic circuitry.
研究领域:
纳米技术
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光学
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材料科学
✓ 已验证
DOI
PubMed
JOURNAL OF ALLOYS AND COMPOUNDS
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2024
·
IF 5.8
Wenbing Huang,Haojie Yu,Li Wang,Dingning Chen,Xudong Wu,Yanhui Zhang,Jiawen He,Chenguang Ouyang,Lei Zhang
Electrical contact materials (ECMs) play a pivotal role in maintaining the stability and efficiency of electrical instruments and electronic devices by regulating the current flow. As an essential member of ECMs, W-Ag matrix composite ECMs (W-Ag-MC-ECMs) are integral, demonstrating commendable resistance to welding and arc erosion. However, the limited wettability between the two phases curtails their broader applications. Herein, Ag-Cu and Ag-Ni bimetallic layer-encapsulated tungsten powders were designed and successfully synthesized through a two-step electroless plating process. Subsequently, the W-Ag-MC-ECMs were fabricated following the powder metallurgy route, including the solution ball milling process and the spark plasma sintering technique. The results indicated that Cu-Ag solid solution and Ni with a metal binder effect could strengthen the interface bonding, which can dramatically improve the microhardness (up to 182HV), strength (up to 600 MPa), ductility (up to 24 %) and resistance to arc erosion (nearly two times longer service life). In addition, during the arc erosion, attributed to the Cu-Ag solid solution effect of W@Ag@Cu/Ag-MC-ECMs and solution-strengthening effect of W@Ag@Ni/Ag-MC-ECMs, the work function increases and the arc energy decreases, which reduces mass loss and extends the service life of the contacts.
研究领域:
材料科学
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电气工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2025
·
IF 3.9
Zhang Guoliang,Dong Junting,Liu Chunying,Yang Duo,Li Yang
Friction and wear are the main factors limiting the reliability and service life of electrical contact materials and equipment. To address this issue, this study proposes an innovative solution that leverages the synergistic effect of nanomaterials. A composite structure consisting of graphene nanosheets (GNSs) and silver nanospheres (SNS) was successfully constructed through in situ reduction. This structure integrated the synergistic friction-reducing mechanisms of rolling elements and nanosheet layers. The conductivity of LP108/0.15 wt% SNS–GNSs-20 was increased by 11 times compared with that of the pure ionic. The LP108/0.20 wt% SNS–GNSs-5 compound lubricant demonstrated excellent friction-reducing effects without current. The average coefficient of friction was decreased to 0.07003, and the wear volume was significantly reduced by 92.62%. As for the current-applied conditions, the tribological properties of this composite lubricant are further improved, with the COF reduced to 0.06866 and the wear volume reduced by 90.93%. This phenomenon was attributed to the synergistic effects of the “rolling ball” mechanism of spherical materials and the “nanosheet slip” of 2D materials. The nanocomposites facilitated filling, rolling, and self-repairing processes on the metal wear scars, thereby significantly reducing friction and wear. The results highlight the considerable potential of novel SNS–GNSs nanocomposites as lubricant additives in electronically controlled friction applications.
研究领域:
摩擦学
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材料科学
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纳米技术
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电气工程
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）