Synthesis of Al2O3/AlN composite powders by plasma processed Al2O3with various additives

2004 ◽  
Vol 19 (5) ◽  
pp. 1356-1363 ◽  
Author(s):  
F.Y.C. Boey ◽  
X.L. Zhao ◽  
A.I.Y. Tok

A novel method was developed to produce Al2O3/AlN composite powders. The composite powders were synthesized by the direct nitridation of Al2O3using various additives by plasma processed with two different types of gas (Ar/N2and N2plasma). The effects of these two different plasma gases and additives on the formation of the Al2O3/AlN composites were studied. The x-ray diffraction results in the composite powders showed that the cubic AlN was converted to the major phase while transient γ–Al2O3was the minor phase when the composite powder was fully melted using nitrogen as the sole working gas. In contrast, the main phase was still α–Al2O3when the composite powder was not well melted using the mixture of argon and nitrogen as the working gas. Carbon was found as an effective conversion additive to increase the cubic AlN of this composite powder up to 49 vol%. The reaction mechanism of forming this composite powder was also analyzed.

2021 ◽  
Vol 9 (8) ◽  
pp. 1637-1641
Author(s):  
Abhishek Abhishek

Introduction: Mrityunjaya Rasa is a Herbo-Mineral formulation, mentioned in Jwara Chikitsa along with various Anupana like Madhu, Aardraka Swarasa, and Jeeraka Kashaya with Guda. Ingredients like Shudha Hingula, Shudha Gandhaka, Shudha Vatsanabha, Shudha Tankana, Pippali and Maricha with properties of Tikta, Katu Rasa Teekshna Guna and Deepana-Pachana, Swedajanana, Yogavahi and Jwaraghna action show the significant result on various types of fever. To attain desired qualities in the finished product, it is much needed to check efficacy on modern parameters for standardization purposes. Thus, Mrityunjaya Rasa was subjected to X- ray diffraction spectroscopy to ensure SOPs followed for preparation. Aim: The study aimed to analyse the results of X-ray diffraction spectroscopy of Mrityunjaya Rasa. Materials and Methods: X-ray diffraction spectroscopy of Mrityunjaya Rasa was carried out at MIT–central instrumentation facility – innovation centre, Manipal, Udupi. Results: XRD study indicates that Mrityunjaya Rasa contains HgS (cinnabar), mercury sulphide in major phase and borax and elements Na, Ca, Mn, Mg, K, P, Zn, C, Cl2, Fe and B in minor phase. Conclusions: Mrityunjaya Rasa contains HgS (cinnabar), mercury sulphide in major phase and borax and other elements like Na, Ca, Mn, Mg, K, P, Zn, C, Cl2, Fe, and B are also present. Compounds and elements are present due to ingredients and Shodhana media which were used. This study can be a path for establishing the thumbprint of SOP for Mrityunjaya Rasa, a herbomineral compound formulation. Keywords: Mrityunjaya Rasa, XRD, HgS, S, Borax, Na, Ca, Mn etc.


2011 ◽  
Vol 364 ◽  
pp. 368-371 ◽  
Author(s):  
Ibrahim Norfadhilah ◽  
Mohamad Hasmaliza ◽  
Zainal Arifin Ahmad ◽  
J. Banjuraizah

Cordierite was synthesized via glass-route using mineral and pure oxide material. Kaolin, talc, dolomite, magnesia, alumina, silica, and calcium oxide were mixed and melted. CaO from mineral and pure oxide was added in order to investigate the properties of each material in cordierite system. Sample was characterized using X-ray diffraction (XRD) analysis and dilatometer testing. The result showed that when 5wt% CaO from mineral (C5 Min) was added and sintered at 900°C, α-cordierite exist as major phase and anorthite as a minor phase. While for a sample consists of 5wt% CaO from pure oxide (C5 Ox), α-cordierite was present as major phases, µ-cordierite and anorthite as minor phases. Crystallite sizes of each material were in nanorange and crystallite size of C5 Ox was less than C5 Min.


2020 ◽  
Vol 38 (2) ◽  
pp. 219-227
Author(s):  
Sumetha Suwanboon ◽  
Sarunya Klubnuan ◽  
Mukdawan Homkaew ◽  
Pongsaton Amornpitoksuk

Abstractβ-Ni(OH)2/ZnO composite powders were successfully synthesized by hydrothermal method at 180 °C for 15 h whereas NiO/ZnO composite powders formed after the as-prepared powders were calcined at 800 °C for 1 h in air. The X-ray diffractometer (XRD), scanning electron microscope (SEM), UV-Vis spectrophotometer were used to characterize the phase, particle shape as well as size and optical properties, respectively. In this system, it was found that ZnO is a major phase while β-Ni(OH)2 and NiO are a minor phases. The altered particle shape of ZnO was influenced by addition of Ni(CH3COO)2·6H2O whereas the particle shape of the minor phase was changed due to the calcination process. The optical band gap decreased when the amount of minor phase increased. For photocatalytic study, it was found that 6 mol% β-Ni(OH)2/ZnO composite powders exhibited the best decolorization of methylene blue aqueous solution.


2012 ◽  
Vol 503-504 ◽  
pp. 459-462
Author(s):  
Zhong Quan Ma ◽  
Ke Gao Liu

The nickel sulfides of NiS and NiS2 have been synthesized successfully at 180 °C and 160 °C by hydrothermal method from NiCl2•6H2O, S powder and NaOH. The phases and morphology of the products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) respectively. Experimental results show that, the major phase of the powder product obtained at 180 °C is NiS2. The Ni-S powder obtained at 180 °C shows granular and hexagonal shapes with sizes of about 200~300 nm. The product powder obtained at 160 °C has the major phase NiS and minor phase NiS2. The morphology of this product was regular hexagonal flakes with side-length 200nm.


2012 ◽  
Vol 512-515 ◽  
pp. 211-214
Author(s):  
J. Gao ◽  
Z.G. Zou ◽  
F. Long ◽  
C.Y. Xie ◽  
S.S. Chi

The In2Se3/CuSe composite powders with the size in the range of 2-8µm for solar cell were successfully synthesized via using relatively simple solvothermal method at atmospheric pressure by the reaction between InCI3.4H2O, CuCI2.2H2O and Selenious acid and hydrazine hydrate in ethylene glycol.The influences of reaction temperature, reaction time, concentration of solution on the phase and morphology of In2Se3/CuSe composite powders were investigated. The phase and morphology of the products hSubscript textave been well studied by X-ray diffraction (XRD)and scanning electron microscope (SSubscript textEM) techniques.The study revealed that under the conditions of solvothermal method at atmospheric pressure, relative pure In2Se3 and CuSe powder were synthesized at temperatures of 160°C and 100°C respectively. The In2Se3/CuSe of irregular flake composite powders with the average size of 2-8µm had been obtained.The morphology of the products can be controlled by adding different kinds of surfactants such as PVP (Polyvinylpyrrolidone), CTAB (Hexadecyl trimethyl ammonium Bromide) and so on.


Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 721 ◽  
Author(s):  
Jorge A. Ramírez-Gómez ◽  
Javier Illescas ◽  
María del Carmen Díaz-Nava ◽  
Claudia Muro-Urista ◽  
Sonia Martínez-Gallegos ◽  
...  

Atrazine (ATZ) is an herbicide which is applied to the soil, and its mechanism of action involves the inhibition of photosynthesis. One of its main functions is to control the appearance of weeds in crops, primarily in corn, sorghum, sugar cane, and wheat; however, it is very toxic for numerous species, including humans. Therefore, this work deals with the adsorption of ATZ from aqueous solutions using nanocomposite materials, synthesized with two different types of organo-modified clays. Those were obtained by the free radical polymerization of 4-vinylpyridine (4VP) and acrylamide (AAm) in different stoichiometric ratios, using tetrabutylphosphonium persulfate (TBPPS) as a radical initiator and N,N′-methylenebisacrylamide (BIS) as cross-linking agent. The structural, morphological, and textural characteristics of clays, copolymers, and nanocomposites were determined through different analytical and instrumental techniques, i.e., X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Adsorption kinetics experiments of ATZ were determined with the modified and synthesized materials, and the effect of the ratio between 4VP and AAm moieties on the removal capacities of the obtained nanocomposites was evaluated. Finally, from these sets of experiments, it was demonstrated that the synthesized nanocomposites with higher molar fractions of 4VP obtained the highest removal percentages of ATZ.


Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 53
Author(s):  
Adrian Szewczyk ◽  
Adrianna Skwira ◽  
Marta Ginter ◽  
Donata Tajer ◽  
Magdalena Prokopowicz

Herein, the microwave-assisted wet precipitation method was used to obtain materials consisting of mesoporous silica (SBA-15) and calcium orthophosphates (CaP). Composites were prepared through immersion of mesoporous silica in different calcification coating solutions and then exposed to microwave radiation. The composites were characterized in terms of molecular structure, crystallinity, morphology, chemical composition, and mineralization potential by Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM-EDX). The application of microwave irradiation resulted in the formation of different types of calcium orthophosphates such as calcium deficient hydroxyapatite (CDHA), octacalcium phosphate (OCP), and amorphous calcium phosphate (ACP) on the SBA-15 surface, depending on the type of coating solution. The composites for which the progressive formation of hydroxyapatite during incubation in simulated body fluid was observed were further used in the production of final pharmaceutical forms: membranes, granules, and pellets. All of the obtained pharmaceutical forms preserved mineralization properties.


Author(s):  
Peng Liu ◽  
Hongbin Zhang ◽  
Sinong Wang ◽  
Hui Yu ◽  
Bingjie Lu ◽  
...  

AbstractThe crystallinity indices (CrI) of Chinese handmade papers were investigated using the X-ray diffraction (XRD) method. Four Chinese handmade papers, Yingchun, Zhuma, Yuanshu and Longxucao papers were used as model substrates of mulberry bark, ramie, bamboo and Eulaliopsis binata papers, respectively. Two forms of the paper samples, paper sheets and their comminuted powders, were used in this study. The results showed that their XRD patterns belong to the cellulose-I type and Iβ dominates the cellulose microstructure of these paper samples. Moreover, it was found that the microstructures and CrIs of cellulose of these papers were changed by the grinding treatment. This work suggested that the sheet form of the handmade papers is suitable to determine CrI by XRD, despite the contribution of non-cellulosic components in the papers. The order of CrIs for these paper sheet samples was Yingchun, Zhuma, Longxucao and Yuanshu papers. Besides CrIs, differences in cross-sectional areas of the crystalline zone of cellulose can be used for comparing different types of handmade papers. It was also found that the CrIs and crystallite size of paper cellulose varied between the sheet samples and the powder samples, illustrating that the pulverisation has a negative influence on the microstructure of the handmade papers.


Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 732
Author(s):  
Alexander A. Bredikhin ◽  
Aidar T. Gubaidullin ◽  
Zemfira A. Bredikhina ◽  
Robert R. Fayzullin ◽  
Olga A. Lodochnikova

Chiral recognition plays an important role in the self-assembly of soft materials, in particular supramolecular organogels formed by low molecular weight gelators (LMWGs). Out of 14 pairs of the studied racemic and enantiopure samples of alkyl-substituted phenyl ethers of glycerol, only eight enantiopure diols form the stable gels in nonane. The formation of gels from solutions was studied by polarimetry, and their degradation with the formation of xerogels was studied by the PXRD method. The revealed crystalline characteristics of all studied xerogels corresponded to those for crystalline samples of the parent gelators. In addition to those previously investigated, crystalline samples of enantiopure para-n-alkylphenyl glycerol ethers [alkyl = pentyl (5), hexyl (6), heptyl (7), octyl (8), nonyl (9)] and racemic 3-(3,5-dimethylphenoxy)propane-1,2-diol (rac-14) have been examined by single crystal X-ray diffraction analysis. Among 22 samples of compounds 1-14 studied by SC-XRD, seven different types of supramolecular motifs are identified, of which only two are realized in crystals of supramolecular gelators. An attempt was made to relate the ability to gel formation with the characteristics of the supramolecular motif of a potential gelling agent, and the frequency of formation of the motif, required for gelation, with the chiral characteristics of the sample.


2018 ◽  
Vol 74 (12) ◽  
pp. 1684-1691
Author(s):  
Marek L. Główka ◽  
Sylwia Kałużyńska ◽  
Malwina Krause ◽  
Katarzyna Gobis ◽  
Henryk Foks ◽  
...  

Tuberculosis still remains a very important problem, especially its multidrug resistant varieties (MDR-TB). Among the potential tuberculostatics, there are two benzimidazole derivatives, namely 5,6-dimethyl-2-phenylethylbenzo[d]imidazole (1) and (E)-5,6-dimethyl-2-styryl-1H-benzo[d]imidazole (2) which showed significant tuberculostatic activities, better than those of Pyrazinamide and Isoniazyd. Also, the cytotoxicity of 1 appeared promising. The compounds were studied (with the use of X-ray diffraction) in the form of the hemihydrate of 1, C17H18N2·0.5H2O (1a), the methanol hemisolvate of 2, C17H16N2·0.5CH3OH (2a), and the acid oxalate salt of 2, namely (E)-5,6-dimethyl-2-styryl-1H-benzo[d]imidazolium hydrogen oxalate, C17H17N2 +·C2HO4 − (2b). All three structures reveal a similar extended conformation, despite the flexible linker between the two aromatic systems and the different types of strong intermolecular hydrogen bonds. The molecules of 2a are practically planar due to the double bond in the linker, which enables conjugation along the whole molecule, while the molecules of 1a exhibit the possibility of parallel orientations of their aromatic systems, despite the aliphatic (ethyl) linker.


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