scholarly journals Oxidation Behavior of YAG-Al<sub>2</sub>O<sub>3</sub> Coatings Toughened by Pt Nano-Particles

2018 ◽  
Vol 4 (1) ◽  
pp. 16
Author(s):  
Peng Wang
2012 ◽  
Vol 591-593 ◽  
pp. 1071-1074
Author(s):  
Min Wang

Zn and Fe nanoparticles prepared by the arc was used in the present study. It were oxidized by laying in the air The microsturctures, oxygen content and oxygen atoms position in nanoparticles were investigated. The results showed that the effective size of oxidized nanoparticles was about50-100nm, particles with a complete form, Particle radius and dislocation density of Oxidated Zn nanoparticles have not change much compare with Zn nanoparticles.Only the strain increase. Fe nanoparticles oxidation lead particles strain rising sharply, and the dislocation densities have decreased slightly. the oxidation occurs in the surface of Fe nano-particles, and generated Fe2O3, After Zn nanoparticles oxidized,Formed ZnO Particles on the surface.


2012 ◽  
Vol 426 ◽  
pp. 40-43 ◽  
Author(s):  
Hong Yu Wang ◽  
Dun Wen Zuo ◽  
X.F. Li ◽  
Ming Di Wang ◽  
Y.F. Zhao

To study effects of nano-Al2O3p (nanometric Al2O3 particles) on high temperature frictional wear behaviors of the NiCoCrAlY coating (a high temperature protective coating), three NiCoCrAlY coatings strengthened by different contents of nano-Al2O3p were prepared on a Ni-based super alloy by using laser cladding technology and their dry frictional wear behaviors at 500 °C in static air were investigated. The comparison was made with the coating without nano-particles. The results show that the frictional coefficient of the coatings increased with the hardness after adding nano-Al2O3p and the wear resistance of the coatings was enhanced. Among nano-Al2O3p-added coatings, the coating added with 1.0 wt% nano-Al2O3p performs best. The wear rate of the coating is only 58% of the coating without nano-particles. Moreover, the improvement of the oxidation behavior plays an important role in improving the high temperature wear resistance.


Author(s):  
A. K. Datye ◽  
D. S. Kalakkad ◽  
L. F. Allard ◽  
E. Völkl

The active phase in heterogeneous catalysts consists of nanometer-sized metal or oxide particles dispersed within the tortuous pore structure of a high surface area matrix. Such catalysts are extensively used for controlling emissions from automobile exhausts or in industrial processes such as the refining of crude oil to produce gasoline. The morphology of these nano-particles is of great interest to catalytic chemists since it affects the activity and selectivity for a class of reactions known as structure-sensitive reactions. In this paper, we describe some of the challenges in the study of heterogeneous catalysts, and provide examples of how electron holography can help in extracting details of particle structure and morphology on an atomic scale.Conventional high-resolution TEM imaging methods permit the image intensity to be recorded, but the phase information in the complex image wave is lost. However, it is the phase information which is sensitive at the atomic scale to changes in specimen thickness and composition, and thus analysis of the phase image can yield important information on morphological details at the nanometer level.


Author(s):  
J. Liu ◽  
M. Pan ◽  
G. E. Spinnler

Small metal particles have peculiar chemical and physical properties as compared to bulk materials. They are especially important in catalysis since metal particles are common constituents of supported catalysts. The structural characterization of small particles is of primary importance for the understanding of structure-catalytic activity relationships. The shape and size of metal particles larger than approximately 5 nm in diameter can be determined by several imaging techniques. It is difficult, however, to deduce the shape of smaller metal particles. Coherent electron nanodiffraction (CEND) patterns from nano particles contain information about the particle size, shape, structure and defects etc. As part of an on-going program of STEM characterization of supported catalysts we report some preliminary results of CEND study of Ag nano particles, deposited in situ in a UHV STEM instrument, and compare the experimental results with full dynamical simulations in order to extract information about the shape of Ag nano particles.


2012 ◽  
Vol 50 (8) ◽  
pp. 575-582 ◽  
Author(s):  
Dong Bok Lee ◽  
Trinh Wan Trung ◽  
Sun Kyu Kim ◽  
Min Jung Kim ◽  
Seul Ki Kim ◽  
...  

MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3153-3161
Author(s):  
Marco Antonio Juárez Sánchez ◽  
Miguel Ángel Meléndez Lira ◽  
Celestino Odín Rodríguez Nava

AbstractDrug contamination in water is one of the current fields of study. Since 1990, the presence of drugs in drinking water has been a concern to scientists and public. In Mexico, these organic compounds are not efficiently removed in wastewater treatment plants; therefore, alternative methodologies have been studied that allow these compounds to have a high percentage of degradation or be completely degraded. One example of these techniques is heterogeneous photocatalysis which has obtained positive results in the degradation of drugs using ZnO nanoparticles. These are commonly selected for their electrical characteristics, even though they disperse in water and an additional unit operation is required to separate them from the liquid medium. To eliminate drugs with nano particles in a single stage, polycaprolactone-based membranes with adhered ZnO nanoparticles, by means of electrospinning, were prepared to degrade drugs such as diclofenac. The technique used has shown to efficiently break down diclofenac in 4 hours according to the capillary electrophoresis readings.


Sign in / Sign up

Export Citation Format

Share Document