The Effect of H3BO3 Microaddition on Microstructure of Ni/MgO Sintered Compact by Co-Precipitation Method

2013 ◽  
Vol 750 ◽  
pp. 168-171
Author(s):  
Ning Ning Zhou ◽  
Dong Ying Ju ◽  
Wan Yu Ding

In the present work, Ni/MgO powder was prepared by co-precipitation in which CO restore NiO to elemental subtance Ni due to C2O42- was decompose to CO and CO2 at 700°C. As the process of the second sintering, H3BO3 was added into the sintered powder of 700°C and was grinded. Then the powder of H3BO3 added was sintered at 800°C,so that the powder was refined, obviously. Thermogravimetric analysis (TGA) and differential thermal analysis(DTA) was carried out in CO2 flow at 10°C/min. X-ray diffraction (XRD) was carried out on a X-ray diffractometer operated at 20KV and 40mA. The microstructures and morphologies were studied by EPMA and XPS.

1966 ◽  
Vol 44 (8) ◽  
pp. 877-884 ◽  
Author(s):  
R. I. Razouk ◽  
Sh. Nashed ◽  
F. N. Antonious

Seven mixed hydroxides of magnesium and aluminium were prepared, and phase and structural changes accompanying their dehydration were investigated by differential thermal analysis, thermogravimetric analysis, and X-ray diffraction techniques. The differential thermal analysis curves possess 2 peaks corresponding to those of parent hydroxides together with a new peak, and the thermogravimetric analysis curves show slight inflections. X-ray diffraction patterns of the mixed hydroxides possess the characteristic lines of the parent hydroxides together with three to five new intense lines which might indicate the formation of a double hydroxide. When the mixed hydroxides are progressively heated they give rise to products possessing patterns which first become diffuse and ultimately pass mainly into the spinel pattern.Adsorption isotherms of cyclohexane and benzene were measured on the mixed hydroxides and their dehydration products. Specific surface areas calculated by the application of the Brunauer, Emmett, Teller (B.E.T.) equation are in general in good agreement for the two adsorbates. The surface area increases with rise of dehydration temperature to a maximum at 500–600 °C and then decreases with further rise in temperature. This behavior is common to crystalline oxide systems and may be ascribed to the intermingling of decomposition, re-crystallization, and sintering processes. Variations in the molecular ratio of the mixed oxides (as much as 20-fold), and in the method of preparation, do not much alter the surface area.


2000 ◽  
Vol 65 (4) ◽  
pp. 265-274
Author(s):  
Slobodanka Marinkovic ◽  
Aleksandra Kostic-Pulek ◽  
Mirjana Djuricic

Selenite was boiled in LiCl solutions of different concentrations (1 M, 2 M, 3 M, 4 M and 5M) at the respective boiling temperatures and atmospheric pressure. The products were subjected to X-ray diffraction analysis, qualitative infrared analysis, differential thermal analysis, thermogravimetric analysis and microscopic examination. The product obtained in the 1 M LiCl solution was the ?-form of calcium sulphate hemihydrate (?-CaSO4.0.5H2O). In more concentrated LiCl solutons, 2M and 3 M, the ?-form of calcium sulphate hemihydrate (?-CaSO4.0.5H2O) was formed. The product obtained in the 4MLiCl solution was also the ?-form of calcium sulphate hemihydrate, only mixed with the ?-form of calcium sulphate (?-CaSO4). Finally, in the 5 M LiCl solution the ?-form of calcium sulphate or ?-anhydrite was formed.


2018 ◽  
Vol 27 (6) ◽  
pp. 1655-1660 ◽  
Author(s):  
Na Zhang ◽  
Xiaoyu Zhang ◽  
Erbo Shi ◽  
Shiyong Zhao ◽  
Kezhu Jiang ◽  
...  

2014 ◽  
Vol 67 (4) ◽  
pp. 657 ◽  
Author(s):  
Xiuping Li ◽  
Yuchun Zhai ◽  
Peihua Ma ◽  
Rongxiang Zhao

Metal oxide photocatalysts often lead to partial or complete mineralization of organic pollutants. On irradiation with UV-visible light, metal oxides catalyze redox reactions in the presence of air and O2 and water. Using ascorbic acid as a new combustion agent, ZnO was rapidly synthesized. Nano-Zn/CeO2 composites were prepared by a heterogeneous-precipitation method using (NH4)2CO3 as precipitation agent. X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectrometry, ultraviolet spectrophotometry, and differential thermal analysis were used to analyse the microstructures of the synthesized materials. Differential thermal analysis, transmission electron microscopy, and X-ray diffraction analyses indicated that ZnO was coated by CeO2. Herein, a nano-Zn/Ce composite was explored as a catalyst for Rhodamine B photodegradation with a 125-W lamp as the UV radiation source in a batch reactor. The results show the photocatalytic properties of the nano-Zn/Ce composite were superior to ZnO, CeO2, and nano-Ce/Zn composites.


2008 ◽  
Vol 587-588 ◽  
pp. 1019-1023
Author(s):  
Sara Valadas ◽  
Deolinda Tavares ◽  
João Coroado ◽  
António Santos Silva ◽  
Jorge Pedro ◽  
...  

Several mortars from mural paintings were collected from the Misericórdia Church of Odemira and analysed by using different techniques namely X-ray diffraction, thermogravimetric analysis with differential thermal analysis, SEM-EDX, optical microscopy, CHNS elemental analysis and chemical analysis. Microfragments of paint layers were collected and analysed by microchemical analysis. The results showed that the mortars are aerial lime mortars with siliceous aggregates and that the pigments used were mainly pigments from local sources (red and yellow ochre’s and malachite) and small blue.


1972 ◽  
Vol 50 (23) ◽  
pp. 3872-3875 ◽  
Author(s):  
Kim Vo Van ◽  
Fathi Habashi

Anhydrous CU2SO4 was prepared and its X-ray diffraction pattern was established. Differential thermal analysis, thermogravimetric analysis, and X-ray diffraction methods were used to study the effect of heating in different atmospheres. The formation of CU2SO4 as an intermediate in chemical processes has been discussed.


2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.


Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 832
Author(s):  
Edna X. Figueroa-Rosales ◽  
Javier Martínez-Juárez ◽  
Esmeralda García-Díaz ◽  
Daniel Hernández-Cruz ◽  
Sergio A. Sabinas-Hernández ◽  
...  

Hydroxyapatite (HAp) and hydroxyapatite/multi-walled carbon nanotube (MWCNT) composites were obtained by the co-precipitation method, followed by ultrasound-assisted and microwave radiation and thermal treatment at 250 °C. X-ray diffraction (XRD) confirmed the presence of a hexagonal phase in all the samples, while Fourier-transform infrared (FTIR) spectroscopy elucidated the interaction between HAp and MWCNTs. The photoluminescent technique revealed that HAp and the composite with non-functionalized MWCNTs present a blue luminescence, while the composite with functionalized MWCNTs, under UV-vis radiation shows an intense white emission. These findings allowed presentation of a proposal for the use of HAp and HAp with functionalized MWCNTs as potential materials for optoelectronic and medical applications.


Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 440
Author(s):  
Fabiana Pereira da Costa ◽  
Jucielle Veras Fernandes ◽  
Luiz Ronaldo Lisboa de Melo ◽  
Alisson Mendes Rodrigues ◽  
Romualdo Rodrigues Menezes ◽  
...  

Natural stones (limestones, granites, and marble) from mines located in northeastern Brazil were investigated to discover their potential for use in civil construction. The natural stones were characterized by chemical analysis, X-ray diffraction, differential thermal analysis, and optical microscopy. The physical-mechanical properties (apparent density, porosity, water absorption, compressive and flexural strength, impact, and abrasion) and chemical resistance properties were also evaluated. The results of the physical-mechanical analysis indicated that the natural stones investigated have the potential to be used in different environments (interior, exterior), taking into account factors such as people’s circulation and exposure to chemical agents.


2015 ◽  
Vol 827 ◽  
pp. 19-24 ◽  
Author(s):  
Nur Afifah ◽  
Nadia Febiana Djaja ◽  
Rosari Saleh

In this study, the photocatalytic activity of pure Fe- doped ZnO and Fe- doped ZnO/Montmorillonite nanocomposite has been investigated for the degradation of malachite green under UV light irradiation. Both photocatalysts were synthesized using co-precipitation method and characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, Fourier-transform infrared absorption, and electron spin resonance. The results showed that the photocatalytic efficiency is better in the presence of montmorillonite compared to pure Fe- doped ZnO. To detect the possible reactive species involved in degradation of organic dyes control experiments with introducing scavengers into the solution of organic dyes were carried out. It is found that electron plays an important role in the degradation of malachite green.


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