Tribological activity of ionic liquid stabilized calcium-doped ceria nanoparticles

Author(s):  
Bharat Kumar ◽  
Dinesh K Verma ◽  
Kavita ◽  
Rashmi B Rastogi

10% Calcium-doped ceria (CCO) nanoparticles have been synthesized by sol–gel method. Their surface has been modified by surfactants, sodium dodecyl sulfate and 1-decyl-3-methyl imidazolium bis(trifluoromethyl sulfonyl) imide to yield SCCO and IL-CCO respectively. Powder X-ray diffraction patterns of nanoparticles and surface modified nanoparticles are indicative of cubic phase of ceria. Fourier transform infrared spectra confirm the surface modification of nanoparticles, particularly with ionic liquid. Morphology of the as-prepared nanoparticles investigated by field emission scanning electron microscopy, transmission electron microscopy/high-resolution transmission electron microscopy reveals that there is decrease in size of nanoparticles from CCO followed by SCCO and then IL-CCO. Wrapping of nanoparticles by ionic liquid is apparent in the scanning electron microscopy (SEM) and transmission electron microscopic (TEM) images. The tribological activity of the well-characterized nanoparticles has been evaluated at the optimized concentration, 0.2% w/v in paraffin oil under ASTM D4172 and ASTM D5183 test conditions using a four-ball tester. Based on tribological parameters, mean wear scar diameter, average friction coefficient, load-carrying capacity, and loss of frictional power, their relative performance followed the order – IL-CCO > SCCO > CCO. Worn surface analysis by scanning electron microscopy/energy-dispersive X-ray spectroscopy, atomic force microscopy corroborated the tribological performance. The order of the activity could be correlated with the size of the nanoparticles. Moreover, lubricating properties of ionic liquid have been instrumental for the exalted activity of IL-CCO. The presence of heteroatoms of ionic liquid, nitrogen, oxygen, fluorine, sulfur along with calcium and cerium of nanoparticles in energy-dispersive X-ray (EDX) spectroscopy analysis of the wear scar surface lubricated with IL-CCO confirms the vital role of ionic liquid towards the tribological activity.

2020 ◽  
Vol 60 (6) ◽  
Author(s):  
Jan Loskot ◽  
Maciej Zubko ◽  
Zbigniew Janikowski

In the presented research, the methods of scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and transmission electron microscopy were applied to analyse the powder waste obtained by cutting of AW-3103 aluminium alloy using a fibre laser. The scanning electron microscopy allows to analyse the morphology of the waste microparticles, the energy-dispersive X-ray spectroscopy revealed their chemical composition, which was compared with the composition of the original cut material. In the waste powder, mainly plate-like particles were observed that contain almost pure aluminium. X-ray powder diffraction measurements confirmed that the waste powder is composed of aluminium phase with only a slight presence of other phases (magnetite, austenite and graphite) and the transmission electron microscopy revealed the presence of nanoscale particles in this waste powder. Furthermore, it was found that the average size of the microparticles depends on the thickness of the cut material: particles obtained from a thicker workpiece were substantially bigger than those obtained from the thinner material. On the contrary, the dimensions of the workpiece have only a little impact on the particles’ shape and no significant influence on their chemical composition. The results also suggest that the microparticles could be used as an input material for powder metallurgy. But there is also a certain health risk connected with inhalation of such tiny particles, especially the nanoparticles, which can penetrate deep into the human pulmonary system.


1996 ◽  
Vol 11 (6) ◽  
pp. 1367-1372 ◽  
Author(s):  
J.C.L. Chow ◽  
P.C.W. Fung ◽  
H.M. Shao ◽  
C.C. Lam

Pb-substituted Hg-based superconductor of Hg0.66Pb0.33Ba2Ca2Cu3Oy has been fabricated using the sealed quartz tube technique. R- and x-ray diffraction pattern (XDP) measurements show that the specimen has a Tc of 135 K and contains mainly the Hg-1223 phase. Scanning electron microscopy/energy dispersive x-ray analysis (SEM/EDX) and transmission electron microscopy/energy dispersive x-ray analysis (TEM/EDX) were employed to study the texture and chemical composition of the specimen. It is found that the specimen contains round-shaped grains with a mixture of Hg-1223, BaCuO2, and Ca0.85CuO2 phases, square-shaped grains with a formula of PbBa2O3, small single crystals with single Hg-1223 phase, and crystal-like layers with a mixture of Hg-1223 and BaCuO2 phase. We consider that though the doping of Pb can benefit the stabilization of the Hg-1223 phase, it introduces other impurity phases and textures in the specimen at the same time.


2012 ◽  
Vol 174-177 ◽  
pp. 508-511
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang

BiFeO3 polyhedrons had been successfully synthesized via a hydrothermal method. The as-prepared products were characterized by power X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The possible mechanisms for the formation of BiFeO3 polyhedrons were discussed. Though comparison experiments, it was found that the kind of precursor played a key role on the morphology control of BiFeO3 crystals.


2011 ◽  
Vol 412 ◽  
pp. 5-8 ◽  
Author(s):  
Ying Zhang ◽  
Ai Chen ◽  
Hai Rong Wang ◽  
Ze Song Li ◽  
Ying Ping Shen

The present article reports the results of studies related to the synthesis of nanocrystalline ceria powder by combustion process using salt combustion aid. Cerium nitrate as oxidant and urea as fuel were used as reagents, Sodium Chloride was compared as combustion aid. The phase analysis and particle size were compared. The product was characterized by X-ray diffraction, Scanning electron microscopy and Transmission electron microscopy. The results showed that employment of starting fuel with combustion aid resulted in synthesizing nanocrystalline ceria powder with fine agglomerates. By using combustion aid, the energetics of the combustion reaction and particle characteristics have been changed.


1997 ◽  
Vol 3 (4) ◽  
pp. 381-396
Author(s):  
S. Chandra ◽  
D. Van Gemert

Abstract Interior plaster from the Abbot's Palace of the Abbey of Villers-la-Ville, Brabant Wallon province, Belgium has been investigated. It is done by using chemical analysis, x-ray diffraction analysis, scanning electron microscopy, energy dispersive electron spectroscopy, and transmission electron microscopy. It is found that the rendering was made with lime rich mortar and animal hairs. The sand used was very fine and the hairs were very short. The solid constituents and the hairs were uniformly dispersed, which could have been obtained by the addition of some other natural polymer, containing protein.


2009 ◽  
Vol 66 ◽  
pp. 171-174
Author(s):  
Zhao Deng ◽  
Ying Dai ◽  
Wen Chen

Single-crystalline BaTiO3 nanoparticles and BaCO3 nanowires were synthesized respectively through the use of a reverse micelle as a medium in the same Oleic acid/n-octane/H2O system, by changing the H2O2 dosage. Both the phase composition and the morphology can be controled. The samples derived were characterized with X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). The formation mechanism has been fully discussed.


2011 ◽  
Vol 347-353 ◽  
pp. 615-620
Author(s):  
Ying Jia ◽  
Tian Tian Liu ◽  
Cheng Luo

Ce0.67Zr0.33O2 (CZ) nanorods are successfully synthesized by glycol-assisted hydrothermal method using zirconium oxychloride, cerium nitrate and urea, with the presence of sodium hypochlorite. The products are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectra. The catalytic oxidation characters about Pd/CZ three-way catalyst (TWC) prepared with different loads of Pd are also investigated. The results show that the as-prepared Pd/CZ has excellent catalytic oxidation character to CO.


2011 ◽  
Vol 110-116 ◽  
pp. 547-552 ◽  
Author(s):  
Yu Xin Wang ◽  
Jing Xu ◽  
Xing Guo Cheng ◽  
Hong Fang Xu ◽  
Li Jun Liu

ZnO nanostructures with different morphology have been successfully fabricated by a simple relative low temperature approach at 90 °C for 5 h without surfactant assistance. These structures can be easily tailed using varied concentrations of sodium hydroxide (NaOH) and different amounts of the hydrazine hydrate (N2H4·H2O). X-ray diffraction (XRD) result proves the formation of ZnO with wurtzite structure. Microstructure as revealed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicates that the rod-like and chrysanthemum-like ZnO nanostructures contain many radial nanorods, which grow along the [0001] direction. Furthermore, the as-prepared ZnO nanomaterials exhibit high activity on the photo-catalytic degradation of typical persistent organic pollutants (POPs), indicating that they are promising as semiconductor photo-catalysts.


2007 ◽  
Vol 342-343 ◽  
pp. 597-600
Author(s):  
Hyoun Woo Kim ◽  
S.H. Shim ◽  
B.H. O ◽  
S.G. Lee ◽  
S.G. Park ◽  
...  

We have fabricated the iron oxide nanowires directly from iron foils through the simple heating in N2 ambient. We have characterized the samples by means of scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray (EDX) spectroscopy, and selected area diffraction pattern. The EDX spectrum revealed that the nanowires contained elements of Fe and O. The iron oxide nanowires were crystalline with diameters in the range of 30-200 nm. We have discussed the possible growth mechanisms.


Author(s):  
G. Pereira

Previous electron microscopic observations of the spleen have revealed the white pulp to be completely separated from the extravasated blood in the surrounding marginal zone by a strategically-located, double layer of reticular cells ensheathing a coarse reticular fiber. Similarly, a single reticular cell layer has been observed to form a continuous investment for all white pulp capillaries. To test the significance of this apparent isolation of the splenic white pulp from the blood, the distribution and composition of silver deposits in the spleen of argyric rats were determined by transmission and scanning electron microscopy coupled with computer-assisted x-ray analysis.Young male albino rats were made argyric by supplying them for many months with drinking water to which 1.5gm per liter of silver nitrate had been added. Specimens from the spleens of control and argyric animals were prepared for conventional transmission electron microscopy by glutaraldehyde-osmium fixation. For scanning electron microscopy, other specimens were fixed in buffered glutaraldehyde, freeze-dried in vacuo, coated with a thin film of gold- palladium and examined in a Cambridge Stereoscan Mark II.


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