scholarly journals Shell thickness determination for PTFE-PS core-shell nanoparticles using scanning transmission X-ray microscopy (STXM)

2018 ◽  
Vol 50 (11) ◽  
pp. 1077-1082 ◽  
Author(s):  
A. Müller ◽  
S. Swaraj ◽  
K. Sparnacci ◽  
W.E.S. Unger
Keyword(s):  
Shell Thickness ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Thickness Determination ◽  
Scanning Transmission ◽  
Core Shell Nanoparticles

Energy-dispersive X-ray spectroscopy for an atomic-scale quantitative analysis of Pd–Pt core-shell nanoparticles

Microscopy ◽  
2020 ◽  
Vol 69 (1) ◽  
pp. 26-30
Author(s):  
Shin Inamoto ◽  
Yuji Otsuka
Keyword(s):  
Quantitative Analysis ◽  
Shell Thickness ◽  
Dark Field ◽  
Atomic Scale ◽  
Energy Dispersive ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Scanning Transmission ◽  
Core Shell Nanoparticles

Abstract The properties of core-shell nanoparticles, which are used for many catalytic processes as an alternative to platinum, depend on the size of both the particle and the shell. It is thus necessary to develop a quantitative method to determine the shell thickness. Pd–Pt core-shell particles were analyzed using scanning transmission electron microscopy (STEM) and energy-dispersive X-ray spectroscopy (EDX). Quantitative EDX line profiles acquired from the core-shell particle were compared to four core-shell models. The results indicate that the thickness of the Pt shell corresponds to two atomic layers. Meanwhile, high-angle annular dark-field STEM images from the same particle were analyzed and compared to simulated images. Again, this experiment demonstrates that the shell thickness was of two atomic layers. Our results indicate that, in small particles, it is possible to use EDX for a precise atomic-scale quantitative analysis.

scholarly journals Lab and Pilot-Scale Synthesis of MxOm@SiC Core–Shell Nanoparticles

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 649 ◽  
Author(s):  
Àngela Ribes ◽  
Santiago Sánchez-Cabezas ◽  
Andy Hernández-Montoto ◽  
Luis A. Villaescusa ◽  
Elena Aznar ◽  
...  
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Scale Up ◽  
Pilot Scale ◽  
Core Shell ◽  
Matrix Composites ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Scanning Transmission ◽  
Core Shell Nanoparticles

The addition of light ceramic particles to bulk technological materials as reinforcement to improve their mechanical properties has attracted increasing interest in the last years. The metal matrix composites obtained using nanoparticles have been reported to exhibit an improvement of their properties due to the decrease in the size of the ceramic additives to the nanoscale. Additionally, important effects such as the dispersion of the nanoparticles, wettability, and low reactivity can be controlled by the modification of the nanoparticles’ surface. In this work, we present the preparation of core–shell MxOm@SiC nanoparticles with different shell compositions. The accurate and reproducible preparation is developed both at the lab and pilot scale. The synthesis of these core–shell nanoparticles and their scale-up production are fundamental steps for their industrial use as additives in metal matrix composites and alloys. Powder X-ray diffraction and energy dispersive X-ray (EDX) coupled with scanning transmission electron microscopy (STEM) are used to corroborate the formation of the core–shell systems, whereas line scan-EDX analysis allows measuring the average shell thickness.

scholarly journals Synthesis and Advanced Characterization of Polymer-Protein Core-Shell Nanoparticles

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 730
Author(s):  
Erik Sarnello ◽  
Tao Li
Keyword(s):  
Particle Size ◽  
Small Angle ◽  
Core Shell ◽  
Assembly Process ◽  
Shell Nanoparticles ◽  
X Ray ◽  
X Ray Scattering ◽  
Wide Range ◽  
Core Shell Nanoparticles ◽  
Ray Scattering

Enzyme immobilization techniques are widely researched due to their wide range of applications. Polymer–protein core–shell nanoparticles (CSNPs) have emerged as a promising technique for enzyme/protein immobilization via a self-assembly process. Based on the desired application, different sizes and distribution of the polymer–protein CSNPs may be required. This work systematically studies the assembly process of poly(4-vinyl pyridine) and bovine serum albumin CSNPs. Average particle size was controlled by varying the concentrations of each reagent. Particle size and size distributions were monitored by dynamic light scattering, ultra-small-angle X-ray scattering, small-angle X-ray scattering and transmission electron microscopy. Results showed a wide range of CSNPs could be assembled ranging from an average radius as small as 52.3 nm, to particles above 1 µm by adjusting reagent concentrations. In situ X-ray scattering techniques monitored particle assembly as a function of time showing the initial particle growth followed by a decrease in particle size as they reach equilibrium. The results outline a general strategy that can be applied to other CSNP systems to better control particle size and distribution for various applications.

Monodisperse Fe3O4/Fe Core/Shell Nanoparticles with Enhanced Magnetic Property

2011 ◽  
Vol 306-307 ◽  
pp. 410-415
Author(s):  
Li Sun ◽  
Fu Tian Liu ◽  
Qi Hui Jiang ◽  
Xiu Xiu Chen ◽  
Ping Yang
Keyword(s):  
Average Diameter ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Transmission Electron ◽  
Shell Particles ◽  
Core Shell Nanoparticles

Core/shell type nanoparticles with an average diameter of 20nm were synthesized by chemical precipitation method. Firstly, Monodisperse Fe3O4 nanoparticles were synthesized by solvethermal method. FeSO4ž7H2O and NaBH4 were respectively dissolved in distilled water, then moderated Fe3O4 particles and surfactant(PVP) were ultrasonic dispersed into the FeSO4ž7H2O solution. The resulting solution was stirred 2 h at room temperature. Fe could be deposited on the surface of monodispersed Fe3O4 nanoparticles to form core-shell particles. The particles were characterized by using various experimental techniques, such as transmission electron microscopy (TEM), X-ray diffraction (XRD), AGM and DTA. The results suggest that the saturation magnetization of the nanocomposites is 100 emu/g. The composition of the samples show monodisperse and the sides of the core/shell nanoparticles are 20-30nm. It is noted that the formation of Fe3O4/Fe nanocomposites magnetite nanoparticles possess superparamagnetic property.

scholarly journals Influence of Ag@SiO2 with Different Shell Thickness on Photoelectric Properties of Hole-Conductor-Free Perovskite Solar Cells

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2364
Author(s):  
Zhiyuan He ◽  
Chi Zhang ◽  
Rangwei Meng ◽  
Xuanhui Luo ◽  
Mengwei Chen ◽  
...  
Keyword(s):  
Solar Cells ◽  
Shell Thickness ◽  
Perovskite Solar Cells ◽  
Current Gain ◽  
Core Shell ◽  
Counter Electrodes ◽  
Shell Nanoparticles ◽  
Photoelectric Properties ◽  
Photosensitive Layer ◽  
Core Shell Nanoparticles

In this paper, Ag@SiO2 core-shell nanoparticles (NPs) with different shell thicknesses were prepared experimentally and introduced into the photosensitive layer of mesoscopic hole-conductor-free perovskite solar cells (PSCs) based on carbon counter electrodes. By combining simulation and experiments, the influences of different shell thickness Ag@SiO2 core-shell nanoparticles on the photoelectric properties of the PSCs were studied. The results show that, when the shell thickness of 0.1 wt% Ag@SiO2 core-shell nanoparticles is 5 nm, power conversion efficiency is improved from 13.13% to 15.25%, achieving a 16% enhancement. Through the measurement of the relevant parameters of the obtained perovskite film, we found that this gain not only comes from the increase in current density that scholars generally think, but also comes from the improvement of the film quality. Like current gain, this gain is related to the different shell thickness of Ag@SiO2 core-shell nanoparticles. Our research provides a new direction for studying the influence mechanism of Ag@SiO2 core-shell nanoparticles in perovskite solar cells.

Core-Shell SiO2/Ag Composite Spheres Prepared by Electrical Exploding Wire Plasma Technique: Synthesis and Characterization

2021 ◽  
Vol 19 (10) ◽  
pp. 82-88
Author(s):  
Duaa A. Uamran ◽  
Qasim Hassan Ubaid ◽  
Hammad R. Humud
Keyword(s):  
Laser Pulse ◽  
Laser Pulses ◽  
Structural Features ◽  
Optical Absorption Spectroscopy ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Photocatalytic Activities ◽  
Core Shell Nanoparticles

Core-shell nanoparticles (SiO2/Ag) were manufactured by using a two-step process: Electric detonation of Ag. Wire in colloidal solution particles then by using laser pulses, nanoparticles are released. The structural features of these nanoparticles were checked by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The (XRD) study showed the progressive coverage of SiO2/Ag by nanoparticles according to the energies of the laser pulse. Measurements of morphology and EDX confirmed the Core/shell structure with particle size at the nano level. It confirmed that preliminary analysis consists of a SiO2 core and an Ag shell from FESEM. The surface of the microscopic balls (SiO2) has been covered completely and homogeneously with Ag nanoparticles, Moreover, Ultraviolet-Visible, and by optical absorption spectroscopy, the Nanoparticles with core crust SiO2/Ag showed excellent photocatalytic activities at various concentrations and laser pulse energy.

Synthesis of Zn2SiO4@ZnO core-shell nanoparticles and the effect of shell thickness on band-gap transition

2020 ◽  
Vol 240 ◽  
pp. 122144 ◽  
Author(s):  
Zhiyang Li ◽  
Bridgid Wanjala ◽  
George Cernigliaro ◽  
Dan Nawrocki ◽  
Zhiyong Gu
Keyword(s):  
Band Gap ◽  
Shell Thickness ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles
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