scholarly journals The Effect of Calcination Temperature on the Structure and Performance of Nanocrystalline Mayenite Powders

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3476 ◽  
Author(s):  
Katarzyna Berent ◽  
Sebastian Komarek ◽  
Radosław Lach ◽  
Waldemar Pyda
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Calcination Temperature ◽  
Phase Formation ◽  
Crystalline Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Appreciable Increase ◽  
And Performance

The effect of calcination temperature on the structural properties and phase formation of synthesized CaO-Al2O3 nanopowder was investigated and discussed. The calcination products were identified by differential thermal analysis (DTA) and the crystalline phase formation was analyzed by X-ray diffraction (XRD). The obtained results showed that the crystallization started at 460 °C. Finally, the microstructures of the nanoparticles were observed by scanning (SEM) and transmission electron (TEM) microscopes. The investigation showed that an increase in the calcination temperature led to the appreciable increase in the crystallite size and the crystallinity of the final product. The obtained data confirmed that the prepared materials were mayenite with different surface area in the range of 71.18 m2/g to 10.34 m2/g after annealing in the temperature range of 470 °C to 960 °C.

Mullite formation from nonstoichiometric slow hydrolyzed single phase gels

1995 ◽  
Vol 10 (4) ◽  
pp. 912-917 ◽  
Author(s):  
Yong Wang ◽  
William J. Thomson
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Crystalline Phase ◽  
Single Phase ◽  
Formation Temperature ◽  
Mullite Formation ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spinel Formation

A comparative dynamic x-ray diffraction (DXRD) and differential thermal analysis (DTA) study was performed in the investigation of mullite and spinel formation from slowly hydrolyzed single phase gels with Al/Si ratios ranging from 1/1 to 14/1. Both metastable tetragonal mullite and spinel were observed to form at temperatures <1000 °C in the gels with Al/Si ratios <8/1 and mullite transformed to the orthorhombic structure at ∼1250 °C. However, at higher Al/Si ratios, spinel was the only crystalline phase detected at <1000 °C and orthorhombic mullite formed directly at temperatures >1250 °C. As the Al/Si ratio increases, both the tetragonal mullite and spinel formation temperatures decrease while the orthorhombic mullite formation temperature increases. Based on the Al/Si composition where the formation extents of tetragonal mullite and spinel were maximum, their compositions are estimated to be 2Al2O3 · SiO2 and 6A12O3 · SiO2, respectively.

Influence of Heat Treatment on the Structure and Performance of ATP and its Catalyzer

2011 ◽  
Vol 295-297 ◽  
pp. 1510-1515 ◽  
Author(s):  
Yue Bin Lin ◽  
Chun Bo Li ◽  
Yu Fu Zhu ◽  
Ai Hui Liu
Keyword(s):  
Heat Treatment ◽  
Thermal Analysis ◽  
Spectroscopic Analysis ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Treatment Conditions ◽  
Transmission Electron ◽  
Crystal Transition ◽  
And Performance

Taking Attapulgite Clay(ATP) as a carrier, TiO2/ATP precursor was prepared by acid sol-gel method, and then made its composite under different heat-treatment conditions. The structures, dimensions, compositions of the composite are characterized by X-Ray diffraction, transmission electron microscope, thermogravimetric-differential thermal analysis and spectroscopic analysis measurements, respectively. the results show that TiO2/ATP composite increase the crystal transition temperature of TiO2, rutile TiO2emerge in the composite until 800°C, ATP lost its layer constructure and collapse at 850°C.

Synthesis of High-Purity Fe2TiO5 Powders Utilizing a Local Ironstone

2019 ◽  
Vol 964 ◽  
pp. 50-54 ◽  
Author(s):  
Armayani Armayani ◽  
Irhamsyah Andi ◽  
Pratapa Suminar
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Crystallite Size ◽  
Calcination Temperature ◽  
High Purity ◽  
Ball Mill ◽  
Weight Fraction ◽  
Commercial Product ◽  
X Ray Diffraction ◽  
X Ray

The synthesis of Fe2TiO5 powders has been successfully performed by making use of Fe2O3 and TiO2 powders. The Fe2O3 powder was obtained from local ironstone in Tanah Laut, South Kalimantan, while the TiO2 powder was a commercial product. The Fe2O3 powder was obtained from the local ironstone through coprecipitation method on pH 5, followed by calcination at 800 °C for 1 hour. The synthesis of Fe2TiO5 powder was done by mixing the raw powders using Planetary Ball Mill method for 5 hours. Thermogravimetric dan Differential Thermal Analysis (TG-DTA) was performed to estimate the calcination temperature. The milled mixtures were then calcined at temperatures of 700 – 1100 °C. X-Ray Diffraction (XRD) data showed that Fe2TiO5 formation started at 800 °C with a weight fraction of 3.60 wt%. The XRD data also showed that at 1100 °C the Fe2TiO5 formation has completed. The crystallite size of Fe2TiO5 powders was 50 and 66 nm after calcination at 900 and 1100 °C, respectively.

Formation of Structurally Complex U-Phase in Al72Pd12.8Co15.2 Alloy

2013 ◽  
Vol 592-593 ◽  
pp. 517-520
Author(s):  
Ivona Černičková ◽  
Peter Švec ◽  
Emília Illeková ◽  
Dusan Janickovic ◽  
Pavol Priputen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Annealing Conditions ◽  
Transmission Electron ◽  
Compositional Homogeneity ◽  
Scanning Electron

The U-phase in the Al72Pd12.8Co15.2alloy was studied under non-equilibrium (casting, differential thermal analysis) and near-equilibrium (long-term annealing) conditions to consider its compositional homogeneity. In the investigation, scanning electron microscopy including energy dispersive X-ray spectroscopy, X-ray diffraction, transmission electron microscopy, and differential thermal analysis were used. Contrary to the finding reported for the Al69.8Pd13.8Co16.4alloy, the results obtained for the investigated Al72Pd12.8Co15.2alloy did not confirm the compositional heterogeneity of the near-equilibrium U-phase after annealing at 700°C for 2000 h and at 850°C for 500 h.

scholarly journals Synthesis and Mechanism of Tetracalcium Phosphate from Nanocrystalline Precursor

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Jianguo Liao ◽  
Xingze Duan ◽  
Yanqun Li ◽  
Caifeng Zheng ◽  
Zhengpeng Yang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Calcination Temperature ◽  
X Ray Diffraction ◽  
Tetracalcium Phosphate ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
Ir And Raman ◽  
Cooling Methods

Tetracalcium phosphate (TTCP, Ca4(PO4)2O) was prepared by the calcination of coprecipitated mixture of nanoscale hydroxyapatite (HA, Ca10(PO4)6(OH)2) and calcium carbonate crystal (CaCO3), followed by cooling in the air or furnace. The effect of calcination temperature on crystal structure and phase composition of the coprecipitation mixture was characterized by transmission electron microscope (TEM), thermal analysis-thermogravimetry (DTA-TG), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), and Raman spectroscopy (RS). The obtained results indicated that the synthesized mixture consisted of nanoscale HA and CaCO3with uniform distribution throughout the composite. TTCP was observed in the air quenching samples when the calcination temperature was above 1185°C. With the increase of the calcination temperature, the amount of the intermediate products in the air quenching samples decreased and cannot be detected when calcination temperature reached 1450°C. Unexpectedly, the mixture of HA and calcium oxide was observed in the furnace cooling samples. Clearly, the calcination temperature and cooling methods are critical for the synthesis of high-purity TTCP. The results indicate that the nanosize of precursors can decrease the calcination temperature, and TTCP can be calcinated by low temperature.

Preparation and Photocatalysis of Nano-Zn/Ce Composite Oxides

2014 ◽  
Vol 67 (4) ◽  
pp. 657 ◽  
Author(s):  
Xiuping Li ◽  
Yuchun Zhai ◽  
Peihua Ma ◽  
Rongxiang Zhao
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Transmission Electron Microscopy ◽  
Differential Thermal Analysis ◽  
Precipitation Method ◽  
Diffraction Field ◽  
Infrared Spectrometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

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.

Identification of pseudoboehmite in mixtures with phyllosilicates

Clay Minerals ◽  
1994 ◽  
Vol 29 (3) ◽  
pp. 351-359 ◽  
Author(s):  
A. Violante ◽  
P. M. Huang
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Transmission Electron Microscopy ◽  
Differential Thermal Analysis ◽  
Detection Limit ◽  
Clay Minerals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Oriented Samples

AbstractThe influence of kaolinite and montmorillonite on the identification of pseudoboehmite was studied by X-ray diffraction (XRD), differential thermal analysis (DTA), infrared absorption (IR), and transmission electron microscopy (TEM). In the randomly oriented samples containing different proportions of the clay minerals and pseudoboehmite, pseudoboehmite was not easily detectable by XRD even in a sample containing 40% of pseudoboehmite. Preheating of the samples at 110-300°C improved the detection limit to 30%. In samples obtained by mixing suitable amounts of the suspensions of the clay minerals (<2μm)and pseudoboehmite, the identification of pseudoboehmite was even more difficult. In oriented samples, pseudoboehmite was detectable only when present in amounts >30%, at low full-scale counts per second (1000-400 cps), on preheated samples in the presence of kaolinite, or on the samples that were Mg-saturated and solvated with ethylene glycol in the presence of montmorillonite. Identification of pseudoboehmite in the presence of kaolinite or montmorillonite by DTA, IR or TEM failed, even in samples containing 50% pseudoboehmite. In the presence of both kaolinite and montmorillonite (1:1 w/w), the identification of pseudoboehmite became much more difficult than in the presence of either mineral alone. The presence of pseudoboehmite in soils may, thus, be undetectable by standard clay mineralogical analyses.

scholarly journals Evolution of the Microstructure and Performance of Pd/Ag - Based Thick Conductors

1985 ◽  
Vol 12 (1) ◽  
pp. 41-57 ◽  
Author(s):  
Maria Prudenziati ◽  
Bruno Morten ◽  
Maria Franca Brigatti
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Thick Film ◽  
X Ray Diffraction ◽  
X Ray ◽  
Analytical Technique ◽  
Analysis Techniques ◽  
Edax Analysis ◽  
And Performance ◽  
Microstructure And Performance

Pd/Ag-based inks are probably the most commonly used conductors in thick-film hybrid technology. The evolution of the microstructure of these films was studied on samples fired with isochronal cycles at a peak temperature in the range from 300℃ up to 850℃. The samples were investigated by means of X-ray diffraction, SEM and EDAX analysis techniques; the results of these analyses as well as those of thermogravimetry (TG, DTG) and differential thermal analysis (DTA), enable one to obtain a clear picture of the complex evolution of the microstructure of these conductors, which correlates quite strictly with the performance of the films in terms of resistivity and adhesion.The relevance and limitations of each analytical technique for the examination of thick-film conductors are emphasized.

PENINGKATAN LAJU DISOLUSI ACYCLOVIR DENGAN METODE SISTEM DISPERSI PADAT MENGGUNAKAN POLOXAMER 188

2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Differential Thermal Analysis ◽  
Fourier Transform Infrared ◽  
X Ray Diffraction ◽  
Poloxamer 188 ◽  
X Ray ◽  
Scanning Electron

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.

scholarly journals The Potential for Natural Stones from Northeastern Brazil to Be Used in Civil Construction

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 ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Chemical Resistance ◽  
Mechanical Analysis ◽  
Northeastern Brazil ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Agents ◽  
Natural Stones

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.

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