scholarly journals Copper and Nickel Nanoparticles Prepared by Thermal Treatment of Their Respective Cations Confined in Nanopores through High-Pressure Synthesis

Applied Nano ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 278-288
Author(s):  
Nancy Brodie-Linder ◽  
Johnny Deschamps ◽  
Marianne Bombled ◽  
Nicolas Pasternak ◽  
Fabrice Audonnet ◽  
...  

A new and simple method for preparing confined copper and nickel nanoparticles by thermal treatment of their respective cations inside Mobil Composition of Matter 41 (MCM–41) hydrophobic nanopores is presented here. Surface modified MCM–41 hydrophobic materials were impregnated by using high-pressure treatment with copper II (Cu II) or nickel II (Ni II) aqueous solutions. After pressure release and washing, the remaining metal cations, confined exclusively within the nanopores, were heated, forming metallic nanoparticles. Reduction of the cations by a redox reaction between the hydrophobic organic surface and the confined metal cations is proposed. Transmission electronic microscopy (TEM), selected area electron diffraction (SAED), nitrogen (N2) adsorption at −196 °C (77 K), Fourier transform infrared (FTIR) and thermogravimetric (TGA) analyses evidenced the identification of copper and nickel nanoparticles (NPs).

2020 ◽  
Vol 235 (8-9) ◽  
pp. 333-339
Author(s):  
Julia-Maria Hübner ◽  
Wilder Carrillo-Cabrera ◽  
Raul Cardoso-Gil ◽  
Primož Koželj ◽  
Ulrich Burkhardt ◽  
...  

AbstractThe new samarium germanide SmGe3 is obtained by high-pressure high-temperature synthesis of pre-reacted mixtures of samarium and germanium at a pressure of 9.5 GPa and temperatures between 1073 and 1273 K. SmGe3 decomposes at 470(5) K into SmGe2, α-Sm3Ge5 and a hitherto unknown phase. SmGe3 exhibits a superstructure of the cubic Cu3Au-type. Transmission electron microscopy measurements of crystalline particles and prepared lamellae indicate a high density of defects on the nanoscale. Selected area electron diffraction and elaborate X-ray powder diffraction measurements consistently indicate a 2a0 × 2a0 × 2a0 superstructure adopting space group $Fm\overline{3}m$ with a = 8.6719(2) Å.


Author(s):  
R. E. Ferrell ◽  
G. G. Paulson ◽  
C. W. Walker

Selected area electron diffraction (SAD) has been used successfully to determine crystal structures, identify traces of minerals in rocks, and characterize the phases formed during thermal treatment of micron-sized particles. There is an increased interest in the method because it has the potential capability of identifying micron-sized pollutants in air and water samples. This paper is a short review of the theory behind SAD and a discussion of the sample preparation employed for the analysis of multiple component environmental samples.


2019 ◽  
Vol 74 (4) ◽  
pp. 357-363
Author(s):  
Daniela Vitzthum ◽  
Hubert Huppertz

AbstractThe mixed cation triel borate Ga4In4B15O33(OH)3 was synthesized in a Walker-type multianvil apparatus at high-pressure/high-temperature conditions of 12.5 GPa and 1300°C. Although the product could not be reproduced in further experiments, its crystal structure could be reliably determined via single-crystal X-ray diffraction data. Ga4In4B15O33(OH)3 crystallizes in the tetragonal space group I41/a (origin choice 2) with the lattice parameters a = 11.382(2), c = 15.244(2) Å, and V = 1974.9(4) Å3. The structure of the quaternary triel borate consists of a complex network of BO4 tetrahedra, edge-sharing InO6 octahedra in dinuclear units, and very dense edge-sharing GaO6 octahedra in tetranuclear units.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
I. Kurata ◽  
José A. Flores-Livas ◽  
H. Sugimoto ◽  
H. Takahashi ◽  
H. Sagayama ◽  
...  

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Michael Zoller ◽  
Hubert Huppertz

AbstractThe rare earth oxoborates REB5O8(OH)2 (RE = Ho, Er, Tm) were synthesized in a Walker-type multianvil apparatus at a pressure of 2.5 GPa and a temperature of 673 K. Single-crystal X-ray diffraction data provided the basis for the structure solution and refinement. The compounds crystallize in the monoclinic space group C2 (no. 5) and are composed of a layer-like structure containing dreier and sechser rings of corner sharing [BO4]5− tetrahedra. The rare earth metal cations are coordinated between two adjacent sechser rings. Further characterization was performed utilizing IR spectroscopy.


CrystEngComm ◽  
2020 ◽  
Vol 22 (47) ◽  
pp. 8266-8273
Author(s):  
Chunxiao Wang ◽  
Hong-an Ma ◽  
Liangchao Chen ◽  
Shuai Fang ◽  
Jian Wang ◽  
...  

FEM was used to explain the mechanism of diamond growth defects and methods were proposed to eliminate the growth defects.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3769
Author(s):  
Noelia Pallarés ◽  
Albert Sebastià ◽  
Vicente Martínez-Lucas ◽  
Mario González-Angulo ◽  
Francisco J. Barba ◽  
...  

High-pressure processing (HPP) has emerged over the last 2 decades as a good alternative to traditional thermal treatment for food safety and shelf-life extension, supplying foods with similar characteristics to those of fresh products. Currently, HPP has also been proposed as a useful tool to reduce food contaminants, such as pesticides and mycotoxins. The aim of the present study is to explore the effect of HPP technology at 600 MPa during 5 min at room temperature on alternariol (AOH) and aflatoxin B1 (AFB1) mycotoxins reduction in different juice models. The effect of HPP has also been compared with a thermal treatment performed at 90 °C during 21 s. For this, different juice models, orange juice/milk beverage, strawberry juice/milk beverage and grape juice, were prepared and spiked individually with AOH and AFB1 at a concentration of 100 µg/L. After HPP and thermal treatments, mycotoxins were extracted from treated samples and controls by dispersive liquid–liquid microextraction (DLLME) and determined by HPLC-MS/MS-IT. The results obtained revealed reduction percentages up to 24% for AFB1 and 37% for AOH. Comparing between different juice models, significant differences were observed for AFB1 residues in orange juice/milk versus strawberry juice/milk beverages after HPP treatment. Moreover, HPP resulted as more effective than thermal treatment, being an effective tool to incorporate to food industry in order to reach mycotoxins reductions.


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