Polishing of Aluminum Alloy Using Photocatalyst and Cathilon Dye under Utraviolet Irradiation

2016 ◽  
Vol 1136 ◽  
pp. 321-326
Author(s):  
Takeshi Tanaka

A fundamental study on finishing aided by an ultraviolet ray (generally mashining:referred to as U-RAMR) was conducted to evaluate its applicability to the polishing of aluminum alloy. Qualitative analysis with X-ray photoelectron spectroscopy (XPS) was used to estimate the chemical reaction induced on Al surfaces that were immersed in some solutions. Inductively coupled plasma spectroscopy (ICPS) was employed to quantitatively analyze the amount of oxidized/dissolved Al, Mg and Fe. The following conclusions were obtained by investigation of the aluminum alloy polishing process. Aluminum does not dissolve in TiO2-solution, whereas a small amount of Al dissolves into cathilon dye solution. Although only a small amount of Al dissolves in TiO2-cathilon dye solution in the absence of UV irradiation, the amount of Al dissolved increases slightly under UV irradiation with the formation of oxide, nitrogen oxide and nitride on the Al surface. In addition, a small amount of an aluminum chloride dissolves into TiO2-cathilon dye solution. An Al alloy (A5052) surface was made flat by polishing with TiO2-cathilon dye slurry under UV irradiation.

2018 ◽  
Vol 12 (2) ◽  
pp. 160-169 ◽  
Author(s):  
Takeshi Tanaka ◽  
◽  
Masaru Takizawa ◽  
Akihiro Hata

The polishing of 4H-SiC wafer processed under ultraviolet (UV) irradiation was investigated to verify the phenomena and effectiveness of ultraviolet-ray aided machining (U-RAM). Inductively coupled plasma spectrometry (ICPS) analysis was conducted to quantitatively determine the oxidation/dissolution volume of SiC. X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) were used to qualitatively analyze the 4H-SiC surfaces. These analyses were used to clarify the compounds that are formed/removed by the decomposition of cathilon dye and water during the polishing of 4H-SiC using TiO2-, cathilon- and TiO2-cathilon (mixed) slurries, all of which contained diamond particles. ICPS measurements indicate that a small amount of Si dissolves in aqueous solutions of cathilon- and TiO2-cathilon. XAS and XPS measurements indicate that SiC composes the bulk of the as-received 4H-SiC, and the surface and thin surface form an interface oxide inside SiC. The chemical-mechanical polishing of 4H-SiC using the TiO2-cathilon slurry forms an oxide, interface oxide, oxynitride and nitride. Diamond particles easily remove these compounds by mechanical scratching. It is possible to attain smaller surface roughness and higher polishing efficiency by combination with chemical reaction of TiO2-cathilon slurry and mechanical action of diamond particles under UV irradiation.


1997 ◽  
Vol 497 ◽  
Author(s):  
M. H. Jordão ◽  
J. M. Assaf ◽  
P. A. P. Nascente

ABSTRACTCatalysts containing tungsten and nickel oxides are important in hydrodesulfurization (HDS), hydrogénation (HY), and steam reforming of hydrocarbons. A series of W/Ni/Al2O3 catalysts was prepared by two different methods: (1) coprecipitation of nickel and aluminium hydroxicarbonate from their nitrates, followed by calcination and impregnation of tungsten; (2) precipitation of boehmite from aluminium nitrate, followed by impregnations of nickel, firstly, and tungsten. The nickel content was kept constant, while the amount of tungsten varied from 2.5 to 15.5 wt-%. The resulting oxides were characterized by inductively coupled plasma spectroscopy (ICP), atomic absorption spectroscopy (AAS), X-ray diffraction (XRD), temperature programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS). ICP and AAS were used to determine the W, Ni, and Al concentrations. XRD detected two phases: NiO and NiAl2O4 (no phase containing metallic tungsten was detected). Increasing the amount of W, the quantity of NiAl2O4 rose, the quantity of NiO decreased, and the particle size of NiO enlarged. The TPR profiles presented three peaks: one at about 1000 °C, associated to a very stable phase; for the samples prepared by coprecipitation, the other two peaks corresponded to “free NiO” and a nonstoichiometric aluminate. For the samples prepared by impregnation, those peaks corresponded to NiO and NiAl2O4. XPS identified Al2O3, NiAl2O4, and Al2(WO4)3 for both preparation methods. Increasing the amount of tungsten in the impregnated samples, NiWO4 was also observed.


2020 ◽  
Vol 12 (12) ◽  
pp. 1458-1463
Author(s):  
Li Zhu ◽  
Xiaomeng Chong ◽  
Yu Zhao ◽  
Mingzhe Xu ◽  
Lihui Yin

An inductively coupled plasma spectroscopy method was established to detect 29 elemental impurities in ceftriaxone sodium for injection by nanocomposite, and also used to detect the elemental impurities in the generic, domestic original and foreign original ceftriaxone sodium for injection. This paper for the first time analysed the possible sources of elemental impurities and their potential impacts on the drug quality based on the process. The results showed that zinc and potassium were detected in both the generic drug and the domestic original ceftriaxone sodium for injection, and zinc was not detected but potassium was detected in the foreign original drug; the content of zinc in the generic drug was significantly higher than that in the domestic original drug, and the content of potassium in generic drug and domestic original drug was higher than that in the foreign original drug, according to the process, the elemental impurities may come from the activated carbon or nanocarriers used in the process, and further stability analysis of the samples showed that the stability of the generic drug was slightly lower than that of the original drug, so it was speculated that impurity elements might also be one of the reasons for its instability.


Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 530 ◽  
Author(s):  
Chaoqun Bian ◽  
Xiao Wang ◽  
Lan Yu ◽  
Fen Zhang ◽  
Jie Zhang ◽  
...  

The incorporation of metal heteroatoms into zeolites is an effective modification strategy for enhancing their catalytic performance. Herein, for the first time we report a generalized methodology for inserting metal heteroatoms (such as Sn, Fe, Zn, and Co) into the layered zeolite precursor RUB-36 via interlayer expansion by using the corresponding metal acetylacetate salt. Through this generalized methodology, Sn-JHP-1, Fe-JHP-1, Zn-JHP-1 and Co-JHP-1 zeolites could be successfully prepared by the reaction of RUB-36 and corresponding metal acetylacetate salt at 180 °C for 24 h in the presence of HCl solution. As a typical example, Sn-JHP-1 and calcined Sn-JHP-1 (Sn-JHP-2) zeolite is well characterized by the X-ray diffraction (XRD), diffuse reflectance ultraviolet-visible (UV-Vis), inductively coupled plasma (ICP), N2 sorption, temperature-programmed-desorption of ammonia (NH3-TPD) and X-ray photoelectron spectroscopy (XPS) techniques, which confirm the expansion of adjacent interlayers and thus the incorporation of isolated Sn sites within the zeolite structure. Notably, the obtained Sn-JHP-2 zeolite sample shows enhanced catalytic performance in the conversion of glucose to levulinic acid (LA) reaction.


Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2695 ◽  
Author(s):  
Mhadmhan ◽  
Marquez-Medina ◽  
Romero ◽  
Reubroycharoen ◽  
Luque

We have successfully incorporated iron species into mesoporous aluminosilicates (AlSBA15) using a simple mechanochemical milling method. The catalysts were characterized by nitrogen physisorption, inductively coupled plasma mass spectrometry (ICP-MS), pyridine (PY) and 2,6-dimethylpyridine (DMPY) pulse chromatography titration, powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). The catalysts were tested in the N-alkylation reaction of aniline with benzyl alcohol for imine production. According to the results, the iron sources, acidity of catalyst and reaction conditions were important factors influencing the reaction. The catalyst showed excellent catalytic performance, achieving 97% of aniline conversion and 96% of imine selectivity under optimized conditions.


Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 942 ◽  
Author(s):  
Nicolas Delaporte ◽  
Michel L. Trudeau ◽  
Daniel Bélanger ◽  
Karim Zaghib

In this study, a carbon-coated LiFePO4 (LFP/C) powder was chemically grafted with trifluoromethylphenyl groups in order to increase its hydrophobicity and to protect it from moisture. The modification was carried out by the spontaneous reduction of in situ generated 4-trifluoromethylphenyl ions produced by the diazotization of 4-trifluoromethylaniline. X-ray photoelectron spectroscopy was used to analyze the surface organic species of the modified powder. The hydrophobic properties of the modified powder were investigated by carrying out its water contact angle measurements. The presence of the trifluoromethylphenyl groups on the carbon-coated LiFePO4 powder increased its stability in deionized water and reduced its iron dissolution in the electrolyte used for assembling the battery. The thermogravimetric and inductively coupled plasma atomic emission spectroscopy analyses revealed that 0.2–0.3 wt.% Li was deinserted during grafting and that the loading of the grafted molecules varied from 0.5 to 0.8 wt.% depending on the reaction conditions. Interestingly, the electrochemical performance of the modified LFP/C was not adversely affected by the presence of the trifluoromethylphenyl groups on the carbon surface. The chemical relithiation of the grafted samples was carried out using LiI as the reducing agent and the lithium source in order to obtain fully lithiated grafted powders.


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