Direct Verification of the Core−Shell Structure of Shell Cross-Linked Micelles in the Solid State Using X-ray Photoelectron Spectroscopy

Langmuir ◽  
2002 ◽  
Vol 18 (21) ◽  
pp. 7780-7784 ◽  
Author(s):  
Shiyong Liu ◽  
Yinghua Ma ◽  
Steven P. Armes ◽  
C. Perruchot ◽  
J. F. Watts
Keyword(s):  
Solid State ◽  
Photoelectron Spectroscopy ◽  
Shell Structure ◽  
Core Shell ◽  
X Ray ◽  
Direct Verification ◽  
The Core ◽  
Core Shell Structure

Influence of Nanoparticle Size on Strain at the Core-Shell Interface

2015 ◽  
Vol 662 ◽  
pp. 217-220 ◽  
Author(s):  
Ondrej Milkovič ◽  
Jana Michaliková ◽  
Jozef Bednarčík ◽  
Štefan Michalik
Keyword(s):  
Solid State ◽  
High Energy ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Core ◽  
Structure Of Nanoparticles ◽  
Fe Nanoparticles ◽  
Hall Method ◽  
Core Shell Structure

This work deals with the strain at the core-shell interface of Fe nanoparticles. Series of Fe nanoparticles with various mean diameters were prepared by precipitation in solid state in binary Cu-Fe alloy. Further, nanoparticles were isolated by dissolution of Cu matrix. High-energy X-ray diffraction (XRD) was used to probe structure of nanoparticles. XRD measurements suggest presence of the core-shell structure, where core and shell of the nanoparticles are formed of α-Fe and CuFe2O4 phase, respectively. Strains in core and shell were estimated as a function of nanoparticles size by Williamson-Hall method.

Controlled Synthesis of Core-Shell Structure SiO2 /NaGdF4:Eu3+ Magnetic and Optical Bifunctional Composite

2014 ◽  
Vol 936 ◽  
pp. 359-363
Author(s):  
Yan Li Wu ◽  
Min Liao ◽  
Hai Xin Ding ◽  
Ru Chun Yang ◽  
Dan Dan Xiong ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Shell Structure ◽  
Photo Luminescence ◽  
Core Shell ◽  
Controlled Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Core ◽  
Core Shell Structure ◽  
Shell Composite

The SiO2/NaGdF4:Eu3+ core/shell composite was prepared by a template-mediated method, making monodispersed SiO2 as core and NaGdF4:Eu colloids as shell, the morphology and the core-shell structure of the resulting particles were analyzed by SEM,X-ray diffraction, and the photo-luminescence and magnetic properties of the microspheres were investigated too. The results shows the composite have great potential to be used as homogeneous magnetic/optical bifunctional material.

scholarly journals Unraveling the Core–Shell Structure of Ligand-Capped Sn/SnOxNanoparticles by Surface-Enhanced Nuclear Magnetic Resonance, Mössbauer, and X-ray Absorption Spectroscopies

ACS Nano ◽  
2014 ◽  
Vol 8 (3) ◽  
pp. 2639-2648 ◽  
Author(s):  
Loredana Protesescu ◽  
Aaron J. Rossini ◽  
Dominik Kriegner ◽  
Maxence Valla ◽  
Antoine de Kergommeaux ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Shell Structure ◽  
Core Shell ◽  
X Ray ◽  
The Core ◽  
Surface Enhanced ◽  
Core Shell Structure ◽  
X Ray Absorption ◽  
Nuclear Magnetic

scholarly journals Design of Scorodite@Fe3O4 Core–Shell Materials and the Fe3O4 Shell Prevents Leaching of Arsenic from Scorodite in Neutral and Alkaline Environments

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 523
Author(s):  
Yang Wang ◽  
Zhihao Rong ◽  
Xincun Tang ◽  
Shan Cao
Keyword(s):  
Photoelectron Spectroscopy ◽  
Shell Structure ◽  
Molar Ratio ◽  
Alkaline Solutions ◽  
Arsenic Content ◽  
Core Shell ◽  
X Ray ◽  
Core Shell Structure ◽  
The Stability ◽  
Fe3o4 Core

In recent years, arsenic pollution has seriously harmed human health. Arsenic-containing waste should be treated to render it harmless and immobilized to form a stable, solid material. Scorodite (iron arsenate) is recognized as the best solid arsenic material in the world. It has the advantages of high arsenic content, good stability, and a low iron/arsenic molar ratio. However, scorodite can decompose and release arsenic in a neutral and alkaline environment. Ferroferric oxide (Fe3O4) is a common iron oxide that is insoluble in acid and alkali solutions. Coating a Fe3O4 shell that is acid- and alkali-resistant on the surface of scorodite crystals will improve the stability of the material. In this study, a scorodite@Fe3O4 core–shell structure material was synthesized. The synthesized core–shell material was detected by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Raman, and energy-dispersive X-ray spectroscopy (EDS) techniques, and the composition and structure were confirmed. The synthesis condition and forming process were analyzed. Long-term leaching tests were conducted to evaluate the stability of the synthesized scorodite@Fe3O4. The results indicate that the scorodite@Fe3O4 had excellent stability after 20 days of exposure to neutral and weakly alkaline solutions. The inert Fe3O4 shell could prevent the scorodite core from corrosion by the external solution. The scorodite@Fe3O4 core–shell structure material was suitable for the immobilization of arsenic and has potential application prospects for the treatment of arsenic-containing waste.

Stabilization of silica-coated silver iodide nanoparticles by ethanol-washing

2016 ◽  
Vol 45 (2) ◽  
pp. 99-105
Author(s):  
Yoshio Kobayashi ◽  
Tetsuya Ayame ◽  
Kyosuke Shibuya ◽  
Tomohiko Nakagawa ◽  
Yohsuke Kubota ◽  
...  
Keyword(s):  
Shell Structure ◽  
Silver Iodide ◽  
Colloid Solution ◽  
Core Shell ◽  
Simple Method ◽  
Content Type ◽  
X Ray ◽  
The Core ◽  
Core Shell Structure ◽  
Ethanol Washing

Purpose – This paper aims to propose a simple method for stabilizing silica-coated silver iodide (AgI/SiO2) core-shell particles, of which a colloid solution functions as an X-ray contrast agent. Design/methodology/approach – A colloid solution of AgI nanoparticles was prepared by mixing silver perchlorate and potassium iodide in water. The AgI/SiO2 nanoparticles were fabricated by a sol-gel method using NaOH, H2O and tetraethylorthosilicate in ethanol in the presence of AgI nanoparticles surface-modified with 3-mercaptopropyltrimethoxysilane. Findings – The silica shells of AgI/SiO2 particles were dissolved near the AgI nanoparticle surface, when they were washed by a process composed of centrifugation, removal of supernatant with decantation, addition of water as a washing solution and a shake with a vortex mixer. In contrast, the shells were not damaged by using ethanol as the washing solution, i.e. ethanol-washing. An X-ray photoelectron spectroscopy spectrum of the silica was changed after the ethanol-washing, which indicated that the ethanol-washing had an effect on the chemical bonds in silica. The effect also acted on the silica shells of AgI/SiO2 particles, which did not damage the core-shell structure, i.e. controlled the dissolution of shell. Originality/value – The paper demonstrates that the ethanol-washing is quite useful for stabilizing the core-shell structure composed of the silica shells.

scholarly journals Promoting Effect of the Core-Shell Structure of MnO2@TiO2 Nanorods on SO2 Resistance in Hg0 Removal Process

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 72
Author(s):  
Xiaopeng Zhang ◽  
Xiangkai Han ◽  
Chengfeng Li ◽  
Xinxin Song ◽  
Hongda Zhu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Shell Structure ◽  
Kinetic Studies ◽  
Elemental Mercury ◽  
Core Shell ◽  
Promoting Effect ◽  
The Core ◽  
So2 Resistance ◽  
Core Shell Structure ◽  
Tio2 Shell

Sorbent of αMnO2 nanorods coating TiO2 shell (denoted as αMnO2-NR@TiO2) was prepared to investigate the elemental mercury (Hg0) removal performance in the presence of SO2. Due the core-shell structure, αMnO2-NR@TiO2 has a better SO2 resistance when compared to αMnO2 nanorods (denoted as αMnO2-NR). Kinetic studies have shown that both the sorption rates of αMnO2-NR and αMnO2-NR@TiO2, which can be described by pseudo second-order models and SO2 treatment, did not change the kinetic models for both the two catalysts. In contrast, X-ray photoelectron spectroscopy (XPS) results showed that, after reaction in the presence of SO2, S concentration on αMnO2-NR@TiO2 surface is lower than on αMnO2-NR surface, which demonstrated that TiO2 shell could effectively inhibit the SO2 diffusion onto MnO2 surface. Thermogravimetry-differential thermosgravimetry (TG-DTG) results further pointed that SO2 mainly react with TiO2 forming Ti(SO4)O in αMnO2-NR@TiO2, which will protect Mn from being deactivated by SO2. These results were the reason for the better SO2 resistance of αMnO2-NR@TiO2.

scholarly journals The Core/Shell Structure of CdSe/ZnS Quantum Dots Characterized by X-Ray Absorption Fine Spectroscopy

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Huijing Wei ◽  
Jing Zhou ◽  
Linjuan Zhang ◽  
Fang Wang ◽  
Jianqiang Wang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Shell Structure ◽  
Single Step ◽  
Organic Sulfur ◽  
Core Shell ◽  
X Ray ◽  
The Core ◽  
Absorption Fine ◽  
Core Shell Structure ◽  
X Ray Absorption

Understanding the chemical and physical properties of core/shell nanocrystal quantum dots (QDs) is key for their use in light-emission applications. In this paper, a single-step injection-free scalable synthetic method is applied to prepare high-quality core/shell QDs with emission wavelengths of 544 nm, 601 nm, and 634 nm. X-ray absorption fine structure spectra are used to determine the core/shell structure of CdSe/ZnS quantum dots. Moreover, theoretical XANES spectra calculated by FEFF.8.20 are used to determine the structure of Se and S compounds. The QD samples displayed nearly spherical shapes with diameters of approximately 3.4 ± 0.5 nm (634 nm), 4.5 ± 0.4 nm (601 nm), and 5.5 ± 0.5 nm (544 nm). With XANES results and MS calculations, it is indicated that sphalerite ZnS capped with organic sulfur ligands should be the shell structure. Wurtzite CdSe is the main core structure with a Cd-Se bond length of 2.3 Å without phase shift. This means that different emission wavelengths are only due to the crystal size with single-step injection-free synthesis. Therefore, single-step injection-free synthesis could generate a nearly ideal core/shell structure of CdSe/ZnS QDs capped with an organic sulfur ligand.

USE OF SANS AND SAXS IN STUDY OF NANOPARTICLES

2005 ◽  
Vol 04 (05n06) ◽  
pp. 987-994 ◽  
Author(s):  
P. S. GOYAL ◽  
V. K. ASWAL
Keyword(s):  
Small Angle ◽  
Shell Structure ◽  
Small Angle Neutron Scattering ◽  
Core Shell ◽  
X Rays ◽  
X Ray ◽  
The Core ◽  
X Ray Scattering ◽  
Structure Of Nanoparticles ◽  
Core Shell Structure

Small Angle Neutron Scattering (SANS) and Small Angle X-ray Scattering (SAXS), anong other available techniques, are the nost sought after techniques for studying the sizes and shapes of nanoparticles. The contrast between particle and its surrounding is different for X-rays and neutrons. Thus a combined SANS and SAXS study, at times, provides information about the core and the shell structure of nanoparticles. This paper gives an introduction to the techniques of SANS and SAXS and shows results of a study of core-shell structure for a micelle (nanaoparticle of organic material).

The Microemulsion Method for Preparing TiO2 Coated SiO2 Core-Shell Particles

2014 ◽  
Vol 602-603 ◽  
pp. 59-62
Author(s):  
Jing Xie ◽  
Le Fu Mei ◽  
Li Bing Liao ◽  
Guo Cheng Lv ◽  
Zhi Guo Xia ◽  
...  
Keyword(s):  
Shell Structure ◽  
Sintering Temperature ◽  
Phase Changes ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Core ◽  
Core Shell Structure ◽  
Shell Particles ◽  
Morphology Changes

In this paper, the monodisperse TiO2 particles and TiO2 coated SiO2 core-shell particles were prepared by the method of microemulsion, and the phase and morphology of TiO2 and TiO2 coated SiO2 core-shell structure particles were analyzed by using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). At the same time, the phase changes and morphology changes of the two different kinds of structural particles as the changes of sintering temperature were compared. The results show that when the TiO2 particles were prepared by the method of microemulsion, the content of anatase TiO2 decreased gradually and the rutile TiO2 increased gradually as the sintering temperature increases from 550 °C to 650 °C; the core-shell particles of TiO2 coated SiO2 prepared were anatase when the sintering temperature increases from 600 °C to 800 °C; all of the particles size were about 1μm, the monodispersity of the particles were optimal and the particles were coated evenly, smoothly. Keywords: TiO2; SiO2; core-shell structure

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