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Nickel is a transition element extensively distributed in the environment, air, water, and soil. It may derive from natural sources and anthropogenic activity. Although nickel is ubiquitous in the environment, its functional role ...
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Nickel is a transition element extensively distributed in the environment, air, water, and soil. It may derive from natural sources and anthropogenic activity. Although nickel is ubiquitous in the environment, its functional role as a trace element for animals and human beings has not been yet recognized. Environmental pollution from nickel may be due to industry, the use of liquid and solid fuels, as well as municipal and industrial waste. Nickel contact can cause a variety of side effects on human health, such as allergy, cardiovascular and kidney diseases, lung fibrosis, lung and nasal cancer. Although the molecular mechanisms of nickel-induced toxicity are not yet clear, mitochondrial dysfunctions and oxidative stress are thought to have a primary and crucial role in the toxicity of this metal. Recently, researchers, trying to characterize the capability of nickel to induce cancer, have found out that epigenetic alterations induced by nickel exposure can perturb the genome. The purpose of this review is to describe the chemical features of nickel in human beings and the mechanisms of its toxicity. Furthermore, the attention is focused on strategies to remove nickel from the environment, such as phytoremediation and phytomining.
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Three layers of semibright nickel (SB-Ni), bright nickel (B-Ni) and dispersed SiO_2-containing nickel (D-Ni) have been prepared from a Watts electroplating bath with some organic additives. The influence of the bath additives on t...
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Three layers of semibright nickel (SB-Ni), bright nickel (B-Ni) and dispersed SiO_2-containing nickel (D-Ni) have been prepared from a Watts electroplating bath with some organic additives. The influence of the bath additives on the free corrosion potential of each as-plated nickel layer have been examined in 5 mass% NaCl and 6 mass% Na_2SO_4 solutions. Exposure time in the air after nickel layer preparation assisted more oxide film formation on semi-bright than on bright nickel surfaces. The anodic and cathodic polarization curves of as-plated nickel layers in chloride and sulphate solutions were investigated by using the potentiodynamic technique. In the chloride solution, all of these nickel layers exhibited pitting corrosion and the critical pitting potential, E_(pit), shifts less noble in the order: D-Ni > B-Ni > SB-Ni, while in the sulphate solution the nickel layers were passivated.
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A method has been developed for the determination of traces of arsenic, boron, bismuth, gallium, germanium, phosphorus, lead, antimony, selenium, silicon and tellurium in nickel matrix. The sample was dissolved in HClO4 (similar t...
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A method has been developed for the determination of traces of arsenic, boron, bismuth, gallium, germanium, phosphorus, lead, antimony, selenium, silicon and tellurium in nickel matrix. The sample was dissolved in HClO4 (similar to 150 degrees C) and nickel was settled as crystalline nickelperchlorate [Ni(ClO4)(2)] on cooling. The mixture was ultrasonicated and after the separation of Ni(ClO4)(2), analytes of interest were determined in the supernatant using ICP-OES. Similarly, it was also found that, after the dissolution of nickel in perchloric acid, when the solution temperature was maintained at 100 C, long needle like crystals of nickel perchlorate were formed. The crystals were separated from the mixture and trace elements in the supernatant were determined using ICP-OES. In both methods the matrix removal was > 99% and the recoveries of analytes were in the range 92-97%. The limits of detection for As, B, Bi, Ga, Ge, P, Pb, Sb, Se, Si and Te were found to be 0.18, 0.21, 0.07, 0.06, 0.25, 0.11, 0.09, 0.10, 0.17, 0.20 and 0.07 mu g g(-1) respectively. The procedure was applied for the analysis of a standard reference material nickel oxide (SRM 761, Nickel Oxide No.1, NBS, USA) and the values obtained are in close agreement with the certified values. (C) 2014 Elsevier B.V. All rights reserved.
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An electrochemical approach was made to recover the nickel from plating wastes in the form of activated nickel by incorporating additives such as thiourea,sodium metabisulfite and sodium thiosulfate in the electrolyte .The anodic ...
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An electrochemical approach was made to recover the nickel from plating wastes in the form of activated nickel by incorporating additives such as thiourea,sodium metabisulfite and sodium thiosulfate in the electrolyte .The anodic behaviour of the nickel produced was studied for its suitability in a Watts nickel and chloride free sulfate baths.It was found that the activated nickel produced with sodium metabisulfite and thiourea additives performs similarly to commercially available activated nickel anodes.
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A new synthesis route, based on the hydrolysis of Na-2[Ni(OH)(4)] is presented which leads to pure single crystalline nickel hydroxide with crystal sizes up to 0.25 mm. The effect of varying preparation conditions on the crystal s...
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A new synthesis route, based on the hydrolysis of Na-2[Ni(OH)(4)] is presented which leads to pure single crystalline nickel hydroxide with crystal sizes up to 0.25 mm. The effect of varying preparation conditions on the crystal size is investigated. [References: 11]
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The author explains the most significant sulfidic and oxidic ores and their sources. He enumerates the most important nickel production technologies and their variants as well. In the use of the nickel the author gives some exampl...
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The author explains the most significant sulfidic and oxidic ores and their sources. He enumerates the most important nickel production technologies and their variants as well. In the use of the nickel the author gives some examples such as the production of coins, and several special alloys. The reader will be acquainted with the main production and consumption data, the main product types, the price development, and the electronic market.
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Metal allergy is a common disease that afflicts many people. Nevertheless, the mechanism underlying metal allergy development has not been completely elucidated. Metal nanoparticles might be involved in the development of a metal ...
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Metal allergy is a common disease that afflicts many people. Nevertheless, the mechanism underlying metal allergy development has not been completely elucidated. Metal nanoparticles might be involved in the development of a metal allergy, but the associated details are unknown. In this study, we evaluated the pharmacokinetics and allergenicity of nickel nanoparticles (Ni-NPs) compared with those of nickel microparticles (Ni-MPs) and nickel ions. After characterizing each particle, the particles were suspended in phosphate-buffered saline and sonicated to prepare a dispersion. We assumed the presence of nickel ions for each particle dispersion and positive control and orally administered nickel chloride to BALB/c mice repeatedly for 28 days. Results showed that compared with those in the Ni-MP administration group (MP group), the Ni-NP administration group (NP group) showed intestinal epithelial tissue damage, elevated serum interleukin (IL)-17 and IL-1β levels, and higher nickel accumulation in the liver and kidney. Additionally, transmission electron microscopy confirmed the accumulation of Ni-NPs in the livers of both the NP and nickel ion administration groups. Furthermore, we intraperitoneally administered a mixed solution of each particle dispersion and lipopolysaccharide to mice and then intradermally administered nickel chloride solution to the auricle after 7 days. Swelling of the auricle was observed in both the NP and MP groups, and an allergic reaction to nickel was induced. Particularly in the NP group, significant lymphocytic infiltration into the auricular tissue was observed, and serum IL-6 and IL-17 levels were increased. The results of this study showed that in mice, Ni-NP accumulation in each tissue was increased after oral administration and toxicity was enhanced, as compared to those with Ni-MPs. Orally administered nickel ions transformed into nanoparticles with a crystalline structure and accumulated in tissues. Furthermore, Ni-NPs and Ni-MPs induced sensitization and nickel allergy reactions in the same manner as that with nickel ions, but Ni-NPs induced stronger sensitization. Additionally, the involvement of Th17 cells was suspected in Ni-NP-induced toxicity and allergic reactions. In conclusion, oral exposure to Ni-NPs results in more serious biotoxicity and accumulation in tissues than Ni-MPs, suggesting that the probability of developing an allergy might increase.
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The electrocatalysis toward small molecules, especially small organic compounds, is of importance in a variety of areas. Nickel based materials such as nickel, its oxides, hydroxides as well as oxyhydroxides exhibit excellent elec...
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The electrocatalysis toward small molecules, especially small organic compounds, is of importance in a variety of areas. Nickel based materials such as nickel, its oxides, hydroxides as well as oxyhydroxides exhibit excellent electrocatalysis performances toward many small molecules, which are widely used for fuel cells, energy storage, organic synthesis, wastewater treatment, and electrochemical sensors for pharmaceutical, medical, food or environmental analysis. Their electrocatalytic mechanisms are proposed from three aspects such as Ni(OH)_2/NiOOH mediated electrolysis, direct electrocatalysis of Ni(OH)_2 or NiOOH. Under exposure to air or aqueous solution, two distinct layers form on the Ni surface with a Ni hydroxide layer at the air-oxide interface and an oxide layer between the metal substrate and the outer hydroxide layer. The transformation from nickel or its oxides to hydroxides or oxyhydroxides could be further speeded up in the strong alkaline solution under the cyclic scanning at relatively high positive potential. The redox transition between Ni(OH)_2 and NiOOH is also contributed to the electrocatalytic oxidation of Ni and its oxides toward small molecules in alkaline media. In addition, nickel based materials or nanomaterials, their preparations and applications are also overviewed here.
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The effect of bath additives on the thermal stability of the microstructure and hardness of nanocrystalline Ni foils processed by electrodeposition was studied. Three samples with a thickness of 20 μ m were prepared: one without ...
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The effect of bath additives on the thermal stability of the microstructure and hardness of nanocrystalline Ni foils processed by electrodeposition was studied. Three samples with a thickness of 20 μ m were prepared: one without any additive and two others with saccharin or trisodium citrate additives. Then, the specimens were heat-treated at different temperatures up to 1000 K. It was found that for the additive-free sample the recovery of the microstructure and the reduction of the hardness started only at temperatures higher than 500 K. At the same time, a decrease of the defect density and hardness was observed even at 400 K for the additive-containing films. This was explained by the higher defect density, which increased the thermodynamic driving force for recovery during annealing. At the highest applied temperature (1000 K), this larger thermodynamic driving force resulted in a recrystallization in the sulfur-containing sample, leading to a very low hardness of about 1000 MPa as compared to the additive-free sample (1300 MPa). On the other hand, the sample deposited with trisodium citrate additive showed a better thermal stability at 1000 K than the additive-free sample: the hardness remained as high as 2000 MPa even at 1000 K.
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This work demonstrates the chemical synthesis of two-dimensional nanoflakes of mesoporous nickel/nickel (II) hydroxide (Ni/Ni(OH)2-NFs) using double templates of surfactant self-assembled thin-film and foam of hydrogen bubbles pro...
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This work demonstrates the chemical synthesis of two-dimensional nanoflakes of mesoporous nickel/nickel (II) hydroxide (Ni/Ni(OH)2-NFs) using double templates of surfactant self-assembled thin-film and foam of hydrogen bubbles produced by sodium borohydride reducing agent. Physicochemical characterizations show the formation of amorphous mesoporous 2D nanoflakes with a Ni/Ni(OH)2 structure and a high specific surface area (165 m2/g). Electrochemical studies show that the electrocatalytic activity of Ni/Ni(OH)2 nanoflakes towards methanol oxidation in alkaline solution is significantly enhanced in comparison with that of parent bare-Ni(OH)2 deposited from surfactant-free solution. Cyclic voltammetry shows that the methanol oxidation mass activity of Ni/Ni(OH)2-NFs reaches 545 A/cm2 gcat at 0.6 V vs. Ag/AgCl, which is more than five times higher than that of bare-Ni(OH)2. Moreover, Ni/Ni(OH)2-NFs reveal less charge transfer resistance (10.4 Ω), stable oxidation current density (625 A/cm2 gcat at 0.7 V vs. Ag/AgCl), and resistance to the adsorption of reaction intermediates and products during three hours of constant-potential methanol oxidation electrolysis in alkaline solution. The high-performance electrocatalytic activity of Ni/Ni(OH)2 nanoflakes is mainly derived from efficient charge transfer due to the high specific surface area of the 2D mesoporous architecture of the nanoflakes, as well as the mass transport of methanol to Ni2+/Ni3+ active sites throughout the catalyst layer.
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