The Synthesis and Characterizations of Narrow-Dispersed Copper Nanoparticles

Author(s):  
Wei Yu ◽  
Huaqing Xie ◽  
Lifei Chen ◽  
Yang Li ◽  
Chen Zhang

A controlled synthesis method for preparing narrow-dispersed copper nanoparticles, using water and ethylene glycol as the reaction mediums respectively, has been reported. In order to obtain pure-phase copper nanoparticles using water, the reaction time of 8h is essential. Owing to the reduction property of ethylene glycol, the reaction rate using ethylene glycol is higher. In addition, the amount of reduction agent can reduce largely. Polyvinyl pyrrolidone plays great role on the size of copper particles, and the increasing of polyvinyl pyrrolidone concentration attributes to the smaller dimension particles. The mean diameter is about 4 nm when the concentration of polyvinyl pyrrolidone is 0.5 mmol/L. Polyvinyl pyrrolidone acts as the polymeric capping agents in the reaction, preventing the agglomeration of the copper nanoparticles. When water is the reaction medium, Cu2+ complex is reduced to Cu+ complex firstly, and the further reduction of Cu+ forms the pure copper nanoparticle.

2011 ◽  
Vol 347-353 ◽  
pp. 3379-3383
Author(s):  
Zhi Wei Li ◽  
Xu Xiang ◽  
Zong Min Tian

The synthesis of α-nickel hydroxide has been achieved via a facile liquid-phase precipitation approach, using the mixed solvents of ethylene glycol and water as reaction medium at low temperature. The XRD characterization indicates that pure phase α-Ni(OH)2can be obtained under variable temperature and pH value. The products present a flower-like micro-/nano-structure assembled with curved nanosheets. The nanosheets have the width of 100~500 nm and the thickness of 20~70 nm. The cavities are formed in the structure due to the interconnection of curved nanosheets. The solvents play a key role in the formation of Ni(OH)2with different forms. Pure phase α-Ni(OH)2can only be synthesized in the mixed solvents of ethylene glycol and water. Cyclic voltammetry was applied to test the electrochemical activity of the as-synthesized α-Ni(OH)2. The findings suggest that the α-Ni(OH)2with a micro-/nano-structure exhibits excellent electrochemical activity, which may be considered as a promising candidate of electrode material.


Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1906
Author(s):  
Marissa Pérez-Alvarez ◽  
Gregorio Cadenas-Pliego ◽  
Odilia Pérez-Camacho ◽  
Víctor E. Comparán-Padilla ◽  
Christian J. Cabello-Alvarado ◽  
...  

Copper nanoparticles (CuNP) were obtained by a green synthesis method using cotton textile fibers and water as solvent, avoiding the use of toxic reducing agents. The new synthesis method is environmentally friendly, inexpensive, and can be implemented on a larger scale. This method showed the cellulose capacity as a reducing and stabilizing agent for synthetizing Cellulose–Copper nanoparticles (CCuNP). Nanocomposites based on CCuNP were characterized by XRD, TGA, FTIR and DSC. Functional groups present in the CCuNP were identified by FTIR analysis, and XRD patterns disclosed that nanoparticles correspond to pure metallic Cu°, and their sizes are at a range of 13–35 nm. Results demonstrated that CuNPs produced by the new method were homogeneously distributed on the entire surface of the textile fiber, obtaining CCuNP nanocomposites with different copper wt%. Thus, CuNPs obtained by this method are very stable to oxidation and can be stored for months. Characterization studies disclose that the cellulose crystallinity index (CI) is modified in relation to the reaction conditions, and its chemical structure is destroyed when nanocomposites with high copper contents are synthesized. The formation of CuO nanoparticles was confirmed as a by-product, through UV spectroscopy, in the absorbance range of 300–350 nm.


1994 ◽  
Vol 13 (2) ◽  
pp. 131-134 ◽  
Author(s):  
Lars Aabakken ◽  
Kjerstin S. Johansen ◽  
Else-Berit Rydningen ◽  
Jan E. Bredesen ◽  
Steinar Øvrebø ◽  
...  

1 Osmolal and anion gaps are helpful in the diagnosis and evaluation of intoxications with methanol and ethylene glycol. Reported reference values for osmolal gap and anion gap are -1 (± 6) mosm kg-1 H2O and 16 (± 2) mmol I -1, respectively. However, we have repeatedly found unexplained increased gaps in patients admitted to our department, and the relevance of the established reference values has been questioned. 2 Osmolal and anion gaps were determined in an unselected population of patients consecutively admitted to an emergency medical department. In the case of unexplained gaps, the blood samples were analysed with respect to the presence of alcohols and organic acids. 3 We included all accessible patients admitted during 14 days. Appropriate blood samples were obtained in 177 patients (88 male, 89 female), with a mean age of 65 years (range 17-94). 4 The mean and (standard deviation) for osmolal and anion gaps in our material were 5.2 mosm kg-1 H2O (7.0) and 12.9 mmol/l (4.2). Neither methanol nor ethylene-glycol was detected in serum from any patients. Small amounts of ethanol were found in 5 patients, and high lactate levels explained in part the most extensively increased anion gaps. However, the calculated analytical standard deviation accounted entirely for the variation in our material, and we suggest that the present reference values be adjusted.


2021 ◽  
Vol 25 ◽  
Author(s):  
Neda Reihani ◽  
Hamzeh Kiyani

: An efficient synthesis of 4-arylidene-3-alkylisoxazole-5(4H)-ones has been implemented via the three-component cyclocondensation of aryl(heteroaryl)aldehydes with hydroxylamine hydrochloride and β-ketoesters. The potassium 2,5-dioxoimidazolidin-1-ide has been introduced as the new organocatalyst to facilitate of this heterocyclization. In the current process, three starting materials, including substituted benzaldehydes/heterocyclic aromatic aldehydes, hydroxylamine hydrochloride, and ethyl acetoacetate/propyl acetoacetate/butyryl acetoacetate have been successfully used for the synthesize of the number of substituted isoxazole-5(4H)-ones in good to high yields in ethylene glycol as a green reaction medium at 80 ºC. The low catalyst loading is also a main advantage over the some reported catalysts.


2020 ◽  
Vol 45 (5) ◽  
Author(s):  
V.O. Uduah ◽  
J.J. Gongden ◽  
M.L. Kagoro ◽  
K.K. Gurumyen ◽  
Y.N. Lohdip ◽  
...  

This work presents a dry synthesis of Iron (III) complex with urea isolated from human urine and Fe (III) obtained from iron rust particles. Iron (III), PI (Purified iron rust), was isolated from iron rust in 10% hydrochloric acid, HCl and distilled water respectively. The complex was synthesized via dry-synthesis method using the melted urea as reaction medium. The isolated Fe (III) was characterized by elemental analysis which was done using XRF Cu-Zn method. The complex was prepared in a 1:4 metal to ligand (M-L) ratio. The stoichiometry of reaction indicate a 1:3 ratio of M-L (Fe-U). The complex was characterized by FT-IR, UV-vis, XRF and XRD spectroscopic techniques. The Fe (III) isolate and Fe-U complex shows percentage yields of 35.7% and ~92% respectively. The elemental and oxide composition of Fe and Fe2O3 (i.e., PI) were 40.387% and 57.753% respectively. The results obtained from the characterization of the iron-urea complex, IUC, indicate FT-IR result as symmetric and asymmetric frequencies with peaks of a combination band of Vs (NH) and Vas (NH), C=O and V (C-N) all stretched, XRD showed the crystal to be amorphous. The elemental and oxide composition of the Fe and Fe2O3 in IUC were 40.007 and 44.201 respectively. The results obtained revealed that useful complexes can be synthesized easily from waste materials, such as urine and iron rust particles, which complement Green chemistry.


2012 ◽  
Vol 567 ◽  
pp. 123-126
Author(s):  
Teng Fei Shen ◽  
Man Geng Lu ◽  
Li Yan Liang

In this work, microporous membrane biomaterials based on high weight molecular polylactide (PLA) and low molecular weight poly(ethylene glycol) (PEG) using rapid solvent evaporation method were prepared and investigated. The effect of PEG segments added on the thermal and degradation behaviors was studied. According to the results, produced PLA/PEG biomaterial has lower glass transition temperature (Tg)in comparison with neat PLA. It was also found that the degradation rates of the PLA/PEG biomaterials were significantly increased with adding of PEG, which explained by increasing hydrophilic groups. For better porous fixation, CL-blocked polyisocyanate (CL-bp), which was synthesized from reaction of isophorone diisocyanate (IPDI) with dimethylol propionic acid (DMPA) and Trimethylolpropane (TMP) followed by addition of caprolactam (CL), were introduced. The microporous forms were observed by the scanning electron microscope (SEM), which showed the mean diameters of prepared PLA/PEG microporous were around 10μm.


2018 ◽  
Vol 6 (44) ◽  
pp. 22179-22188 ◽  
Author(s):  
Melissa E. King ◽  
Michelle L. Personick

Iodide-induced kinetic control enables selective surface passivation of palladium through underpotential deposition of copper to generate terraced palladium–copper particles.


2016 ◽  
Vol 59 ◽  
pp. 3-7 ◽  
Author(s):  
Renata Reisfeld ◽  
Viktoria Levchenko ◽  
Agata Lazarowska ◽  
Sebastian Mahlik ◽  
Marek Grinberg

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