scholarly journals Study of metal-polymer copper nanocomposites using the method of UV spectroscopy

2021 ◽  
Vol 11 (1) ◽  
pp. 165-170
Author(s):  
A. A. Ivanova ◽  
A. I. Emel’yanov ◽  
S. A. Korzhova ◽  
A. S. Pozdnyakov
Keyword(s):  
Copper Ions ◽  
Chemical Reduction ◽  
Uv Spectroscopy ◽  
Electronic Devices ◽  
Copper Acetate ◽  
Reduction Reaction ◽  
Molar Ratio ◽  
Copper Particles ◽  
Brown Colour ◽  
Metal Polymer

New polymer copper-containing nanocomposites based on poly-N-vinylimidazole were obtained. The formation of nanocomposites was carried out using the method of chemical reduction of copper ions from a solution of copper acetate with ascorbic acid in an aqueous medium in the presence of a polymer. Nanocomposites were prepared at the polymer:Cu (II) molar ratio of 10:1 and 5:1. The reduction reaction yielded powder nanocomposites of a red-brown colour and having a metallic shine. It was found that the content of copper in the obtained nanocomposites depends on the initial molar ratio of the stabilising poly-N-vinylimidazole and Cu (II), reaching 5.9% and 11.7%. The formation of nanosized copper particles was investigated and confirmed by UV spectroscopy. The optical spectra of aqueous solutions of the obtained copper-containing nanocomposites contained maxima at 537–541 and 646–651 nm, which confirmed the formation of ultradispersed copper in the nanosized state. The obtained copper-containing nanocomposites based on poly-N-vinylimidazole are promising materials for use in medicine and catalysis, as well as in optical, sensor and electronic devices.

Integration of polyelectrolyte enhanced ultrafiltration and chemical reduction for metal-containing wastewater treatment and metal recovery

2015 ◽  
Vol 72 (7) ◽  
pp. 1096-1101 ◽  
Author(s):  
Jui-Hsuan Yu ◽  
Yi-Hsuan Chou ◽  
Yang-Min Liang ◽  
Chi-Wang Li
Keyword(s):  
Removal Efficiency ◽  
Ph Value ◽  
Chemical Reduction ◽  
Sample Pretreatment ◽  
Particle Size Analysis ◽  
Reduction Reaction ◽  
Copper Removal ◽  
Molar Ratio ◽  
Size Analysis ◽  
Copper Particles

Chemical reduction was firstly employed to treat synthetic wastewaters of various compositions prepared to simulate the retentate stream of polyelectrolyte enhanced ultrafiltration (PEUF). With fixed Cu:polyethylenimine (PEI) monomer:dithionite molar ratio, increasing copper concentration increases copper removal efficiency. Under fixed Cu:dithionite molar ratio and fixed Cu concentration, increasing PEI monomer:copper molar ratio decreases copper removal efficiency. The formation of nano-sized copper particles, which readily pass through 0.45 μm filter used for sample pretreatment before residual copper analysis, might be the reason behind the decreasing copper removal efficiency observed. Particle size analysis shows that the size of copper particles, which are formed through reduction reaction, increases with decreasing pH value and increasing reaction time. As ultrafiltration is capable of removing these nano-sized particles, integration of chemical reduction and PEUF is proposed to simultaneously achieve regeneration of polyelectrolyte and recovery of copper in one process. Results show that the proposed process could achieve almost complete copper removal without being affected by reaction pH.

ENPLATE NI-423

Alloy Digest ◽  
1986 ◽  
Vol 35 (11) ◽  
Keyword(s):  
Wear Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
High Speed ◽  
Chemical Reduction ◽  
Electronic Devices ◽  
Electroless Nickel ◽  
Heat Treating ◽  
Corrosion And Wear ◽  
Phosphorus Alloy

Abstract ENPLATE NI-423 is a nickel-phosphorus alloy deposited by chemical reduction without electric current. It is deposited by a stable, relatively high-speed functional electroless nickel process that produces a low-stress coating with good ductility and excellent resistance to corrosion. Its many uses include equipment for chemicals and food, aerospace components, molds and electronic devices. This datasheet provides information on composition, physical properties, and hardness. It also includes information on corrosion and wear resistance as well as heat treating, machining, joining, and surface treatment. Filing Code: Ni-343. Producer or source: Enthone Inc..

Preparation of Silica-Supported Nickel Molybdenum Phosphides by Temperature-Programmed Reduction Technique

2007 ◽  
Vol 124-126 ◽  
pp. 1765-1768 ◽  
Author(s):  
So Yeon Lee ◽  
Yong Kul Lee ◽  
S.Ted Oyama ◽  
Seok Hee Lee ◽  
Hee Chul Woo
Keyword(s):  
Single Phase ◽  
Reduction Rate ◽  
Reduction Reaction ◽  
Molar Ratio ◽  
Infrared Spectrometry ◽  
Molybdenum Oxides ◽  
Temperature Programmed Reduction ◽  
X Ray Diffraction ◽  
Ammonium Hydrogen ◽  
Temperature Programmed

Silica supported nickel molybdenum phosphides (NiMoP/SiO2) were successfully prepared by temperature-programmed reduction (TPR) reaction of phosphorous-impregnated nickel molybdenum oxides (NiMoO4) precursors with hydrogen at relatively low temperatures (530 – 590 oC) and characterized by Fourier transform-Infrared spectrometry (FT-IR), X-ray diffraction (XRD), Electron probe microanalysis (EPMA) and Temperature-programmed reduction reaction (TPR). The process of solid transformation and properties of materials prepared from ammonium hydrogen phosphate (AMP)-impregnated samples were compared with those of phosphide made from phosphoric acid (PAC)-impregnated samples. Results show that the formation of a single NiMoP phase on silica significantly depends on reduction rates, phosphorous sources and phosphorous loadings. A single phase of NiMoP on SiO2 was particularly promoted at a below 5 oC/min of reduction rate and the starting molar ratio of Ni/Mo/P=1/1/1. A single phase of crystalline NiMoP on silica was produced from AMP-impregnated samples, while other phases of MoP, Ni2P, or NiMoP2 were appeared from PAC-impregnated samples with loading. The new phase of NiMoP2 was occurred with increasing phosphorous loading (above Ni/Mo/P=1/1/2.5) as a result of facilitated contact on the surface between the Ni-Mo bimetallic component and the phosphorous reagent

Boiling/Evaporation Heat Transfer Augmentation Using Subchannels-Inserted Metal Porous Media

2013 ◽  
Author(s):  
Kazuhisa Yuki ◽  
Masahiro Uemura ◽  
Koichi Suzuki ◽  
Ken-ichi Sunamoto
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
Electronic Devices ◽  
High Heat Flux ◽  
Transfer Performance ◽  
Power Electronic ◽  
Copper Particles ◽  
Evaporation Heat

Two-phase flow loop system using a metal porous heat sink is proposed as a cooling system of the future power electronic devices with a heat load exceeding 300W/cm2. In this paper, as the first step, the heat transfer performance of the porous heat sink is evaluated under high heat flux conditions and the applicability and some engineering issues are discussed. The porous medium, which is fabricated by sintering copper particles, has a functional structure with several sub-channels inside it to enhance phase-change as well as discharge of generated vapor outside the porous medium. This porous heat sink is attached onto a heating chip and removes the heat by evaporating cooling liquid passing through the porous medium against the heat flow. Experiments using 30 kW of heating system show that the heat transfer performance of a copper-particles-sintered porous medium with the sub-channels exceeds 800W/cm2 in both high and low subcooling cases and achieves 300W/cm2 at a wall temperature of 150 °C (Tin = 70 °C) and 130 °C (Tin = 70 °C). These results prove that this porous heat sink is applicable enough for cooling 300 W/cm2 class of power electronic devices.

Multi-Walled Carbon Nanotubes as Electrocatalyst Supports for H2O2 Reduction Reaction

2013 ◽  
Vol 860-863 ◽  
pp. 831-834
Author(s):  
Dan Zheng ◽  
Ting Fang Yang ◽  
Zhang Fei Guo
Keyword(s):  
Cyclic Voltammetry Curve ◽  
Chemical Reduction ◽  
Reduction Reaction ◽  
Carbon Substrate ◽  
Acid Media ◽  
Multi Walled Carbon Nanotube ◽  
Multi Walled Carbon Nanotubes ◽  
Current Densities ◽  
Reaction Activation Energy ◽  
Walled Carbon Nanotubes

This work studies the use of Multi-walled carbon nanotube (MWCNT) as catalyst supports for H2O2 electro-reduction in acid media. Using impregnation-chemical reduction method, we prepared Pt-Ag/CNTs, Pt-Co/CNTs, Pt-Ag/C and Pt-Co/C nanocatalysts. Four catalysts were analyzed by XRD and TEM. Their electrochemical performance was studied via cyclic voltammetry curve. The results show that: the nanoparticles have a better dispersion on CNTs substrate than on XC-72 carbon substrate. Comparing with Pt-Ag and Pt-Co on XC-72 carbon substrate, the H2O2 reduction reaction activation energy of catalysts on CNTs substrate is bigger, and the peak current densities of catalysts on CNTs substrate are larger than that on XC-72 carbon.

scholarly journals ELECTROCHEMICAL ACTIVITY OF PtM (M=Co, Cu, Ni) CATALYSTS SUPPORTED ON CARBON VULCAN FOR OXYGEN REDUCTION REACTION (ORR) IN FUEL CELLS

2018 ◽  
Vol 56 (2A) ◽  
pp. 81-88 ◽  
Author(s):  
Vu Thi Hong Phuong
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Chemical Reduction ◽  
Low Cost ◽  
Reduction Reaction ◽  
Proton Exchange ◽  
Carbon Powder ◽  
Galvanic Replacement ◽  
H2o2 Formation ◽  
Cost Efficient

PEMFC - proton exchange membrane fuel cell is electrochemical devices producing electricity and heat from reaction between a fuel (often hydrogen) and oxygen. Therefore, energy production is generally clean and effective without burning the fuel like the tradition way in combustion engines. The obstacles encountered fuel cell commercialization are mainly due to expensive catalyst materials (Platinum) and long-term instability performance. For this reason, numerous investigations have been undertaken with the goal of developing low-cost, efficient electrocatalysts that can be used as alternatives to Pt. In this paper, a two-step procedure at room temperature was applied to prepare a bimetallic Pt-M(M = metal) supported carbon Vulcan. First, the chemical reduction of M metal ions by sodium borohydride in the presence of carbon powder is performed. Second, the partial galvanic replacement of M particle layers by Pt is achieved upon immersion in a chloroplatinate solution. The major size of synthesized metallic particles was around 2-3 nm. From the slope of Koutecky-Levich plot for ORR using PtM/C materials as catalysts it was found that the overall electron transfer number ranged from 3 to 4, leading to the suggestion of H2O2 formation as an intermediate of the ORR.

One-pot synthesis of the new Hydroxamic acid and its complexes with metals

2022 ◽  
Vol 19 ◽  
Author(s):  
Gulu Abbasova ◽  
Ajdar Medjidov
Keyword(s):  
Nmr Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Hydroxamic Acid ◽  
Uv Spectroscopy ◽  
Molar Ratio ◽  
One Pot ◽  
Ethanol Medium ◽  
Physicochemical Methods ◽  
Colored Complexes ◽  
First Time

Abstract: A one-pot conversion of 2-hydroxy-1-naphthoic aldehyde to hydroxamic acid was described. An efficient photoorganocatalytic method of synthesis was developed. The obtained hydroxamic acid was identified by various physicochemical methods such as IR, UV- and NMR-spectroscopy. Solid colored complexes of copper (II) and iron (II), respectively, green and brown colours with the obtained hydroxamic acid were synthesized in ethanol medium for the first time. The molar ratio of ligand and metal in the complex was 2:1. Their structures were established using IR, UV- spectroscopy and thermogravimetric analysis.

scholarly journals Preparation of Carbon Aerogel Electrode for Electrosorption of Copper Ions in Aqueous Solution

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1864 ◽  
Author(s):  
Ziling Cao ◽  
Chen Zhang ◽  
Zhuoxin Yang ◽  
Qing Qin ◽  
Zhihua Zhang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Copper Ions ◽  
Sol Gel ◽  
Copper Ion ◽  
Carbon Aerogel ◽  
Double Layers ◽  
Molar Ratio ◽  
Adsorption Effect ◽  
Control Variate

Carbon aerogel (CA) has a rich porous structure, in which micropores and mesopores provide a huge specific surface area to form electric double layers. This property can be applied to the application of capacitive deionization (CDI). The adsorption effect of CA electrode on Cu2+ in an aqueous solution was explored for solving heavy metal water pollution. The CAs were synthesized by a sol-gel process using an atmospheric drying method. The structure of CAs was characterized by scanning in an electron microscope (SEM) and nitrogen adsorption/desorption techniques. The adsorption system was built using Cu2+ solution as the simulation of heavy metal pollution solution. The control variate method was used to investigate the effect of the anion species in copper solution, the molar ratio of resorcinol to catalyst (R/C) of CA, and the applied voltage and concentration of copper ion on the adsorption results.

Co/Co3O4 Based Nanoparticles and Their Polymer Composites for Tuned Electromagnetic Interference Shielding Application

2020 ◽  
Vol 20 (5) ◽  
pp. 2847-2857
Author(s):  
Madhvi Tiwari ◽  
M. A. Arya ◽  
Priyesh V. More ◽  
Saurabh Parmar ◽  
Suwarna Datar ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Reduction Method ◽  
Chemical Reduction ◽  
Electronic Devices ◽  
Coconut Oil ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Chemical Reduction Method ◽  
Cobalt Oxide Nanoparticles ◽  
Network Analyser

The magnetic properties of the metal nanoparticles (NPs) can play remarkable role in electromagnetic interference shielding (EMI Shielding) of many defence and commercial electronic devices. In the present work, coconut oil and PVA capped magnetic cobalt/cobalt oxide nanoparticles (Co/Co3O4 NPs) were synthesized by chemical reduction method and impregnated in polymer matrix to verify their EMI shielding behaviour. The coconut oil capped Co/Co3O4 NPs with presence of hcp and fcc phases were prepared in the size domain of 7–10 nm and the effect of surfactant (the oil) on size and oxidation state was studied by varying the ratios. The shielding efficiencies of Co/Co3O4 NPs PVA nanocomposites were analysed by using vector network analyser (VNA) in X- and Ku-band ranging from 8 GHz–18 GHz. The VNA results showed increased shielding efficiency with increasing concentration of NPs.

scholarly journals Patterned Metal/Polymer Composite Film with Good Mechanical Stability and Repeatability for Flexible Electronic Devices Using Nanoimprint Technology

Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 651
Author(s):  
Xu Zheng ◽  
Qing Wang ◽  
Jinjin Luan ◽  
Yao Li ◽  
Ning Wang
Keyword(s):  
Mechanical Properties ◽  
Composite Film ◽  
Polymer Composite ◽  
Interfacial Adhesion ◽  
Metal Film ◽  
Mechanical Stability ◽  
Electronic Devices ◽  
Composite Films ◽  
Polymer Composite Film ◽  
Metal Polymer

Mechanical stability and repeatability are significant factors for the application of metal film flexible electronic devices. In this work, patterned metal/polymer composite films with good mechanical stability and repeatability were fabricated through nanoimprint technology. The mechanical properties characteristic of metal/polymer composite films were exhibited by resistance change (ΔR/R0) after cyclic tension and bending loading. It was found that the ΔR/R0 and error line of patterned metal/polymer composite film was far lower than the other control groups for repeated experiments, which indicates that patterned metal film has excellent mechanical properties and repeatability. The double cantilever beam method was employed to measure the interfacial adhesion properties of composite films. The average interfacial adhesion of patterned metal/polymer composite films is shown to be over 2.9 and 2.2 times higher than that of metal film deposited on bare polymer and metal nanowire-treated polymer substrates, respectively.

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