The Effects of Particle Size and Morphology of Raw Materials on the Properties of MoSi2 Synthesized by SHS

2013 ◽  
Vol 319 ◽  
pp. 213-218 ◽  
Author(s):  
Ying Zhou ◽  
Cai Li Wei ◽  
Guo Tian Ye ◽  
Chen Yong Liu
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Secondary Phase ◽  
Combustion Products ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
High Temperature Synthesis ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Grinding Time

In this work, the influences of the particle size and morphology of raw materials on the formation of MoSi2 by self-propagating high-temperature synthesis (SHS) were investigated. A series of Si powders with different particle sizes and Mo powders with different morphologies were obtained by grinding for 1, 5 and 10 hours, respectively. X-ray diffraction pattern characterization (XRD) and scanning electron microscopy (SEM) were used to characterize the samples. It was found that, the phase compositions and morphologies of the combustion products depended on the particle size and morphology of the raw materials. The particle sizes of Si powders decreased with increasing the grinding time, and a secondary phase of Mo5Si3 was detected in the obtained MoSi2 powders when the smallest particle size of Si powders was about 1μm. While, the particle sizes of Mo powders increased with increasing the grinding times, and the obtained MoSi2 showed massive flaky structures, which were similar to the morphologies of Mo particles.

scholarly journals Formation of NanoscaleMg(x)Fe(1-x)O  (x=0.1,0.2,0.4)Structure by Solution Combustion: Effect of Fuel to Oxidizer Ratio

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Mohsen Ahmadipour ◽  
K. Venkateswara Rao ◽  
V. Rajendar
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Crystallite Size ◽  
Average Crystallite Size ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
Solution Combustion ◽  
X Ray ◽  
Particle Size And Morphology ◽  
Size And Morphology

Mg(x)Fe(1-x)O(magnesiowustite) nanopowder samples synthesized by solution-combustion method and fuel to oxidizer ratio (Ψ=1,1.25) are used as a control parameter to investigate how particle size and morphology vary withΨ. The method is inexpensive and efficient for synthesis of oxide nanoparticles. The average crystallite size ofMg(x)Fe(1-x)Onanoparticles was estimated from the full-width-half maximum of the X-ray diffraction peaks of powders using Debye-Scherrer’s formula; the average crystallite size varies from 16 nm to 51 nm. From X-ray diffraction analysis, it was observed thatMg(x)Fe(1-x)Onanoparticles have cubic structure. The particle size measured by particle size analyzer ranges from 37.7 nm to 73 nm which is in the order of XRD results. Thermal analysis was done by thermal gravimetric-differential thermal analyzer. The particle size and morphology of the synthesized powder were examined by transmission electron microscope and scanning electron microscope. The crystal size and particle size were compared with some of the most recently published research works by XRD and TEM. FTIR conforms formation of theMg(x)Fe(1-x)O.

Preparation of ZrB2 Powders with Different Morphologies by Pressureless Reactions

2016 ◽  
Vol 697 ◽  
pp. 39-43
Author(s):  
Wan Xiu Hai ◽  
Yi Hui Huang ◽  
Yong Jiang ◽  
Zhen Bang Wei
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Raw Materials ◽  
Reaction System ◽  
Muffle Furnace ◽  
Reaction Systems ◽  
Air Atmosphere ◽  
Chemical Reaction System ◽  
Particle Size And Morphology ◽  
Size And Morphology

The ZrB2 powders with different morphology were prepared by pressureless reactions, using ZrO2, B2O3, B4C, and graphite as raw materials. Three kinds of chemical reaction system were employed. The ratio of raw materials and reaction temperature were adjusted to prepare ZrB2 powders of different morphology and particle size. The phase composition and purity of the as-prepared powders were analyzed by XRD, while the morphology and particle size were analyzed by SEM. The ZrB2 powders were purified by removing impurities at 600 °C in a muffle furnace in air atmosphere. The results showed that in the reaction systems of ZrO2-B2O3-C and ZrO2-B4C-C, the ZrB2 could be generated at 1500 °C. The morphology of the as-prepared ZrB2 powders were particles, rod-like or near spherical for ZrO2-B2O3-C system and particles for ZrO2-B4C-C system. In the reaction system of ZrO2, B2O3, B4C, and C with a mole ratio of 3:2:1:8, the ZrB2 powders with high purity could be produced at 1700 °C. The ZrB2 powder was near spherical. After heat treatment, the particle size and morphology changed to some extent.

scholarly journals Effects of different Sn contents on formation of Ti2SnC by self-propagating high-temperature synthesis method in Ti-Sn-C and Ti-Sn-C-TiC systems

2014 ◽  
Vol 32 (4) ◽  
pp. 696-701 ◽  
Author(s):  
Hong-Yan Sun ◽  
Xin Kong ◽  
Wei Sen ◽  
Zhong-Zhou Yi ◽  
Bao-Sen Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Raw Materials ◽  
Synthesis Method ◽  
Combustion Products ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
X Ray ◽  
High Temperature Synthesis ◽  
Scanning Electron

AbstractEffect of different Sn contents on combustion synthesis of Ti2SnC was studied using elemental Ti, Sn, C and TiC powders as raw materials in the Ti-Sn-C and Ti-Sn-C-TiC system, in which the molar ratio of Ti/C was set as 2:1. The reaction mechanism for the formation of Ti2SnC was also investigated. The results showed that the amount of Ti2SnC in combustion products firstly increased with increasing of Sn content (0.6 to 0.8 mol), and then decreased with further increasing of Sn content (1.0 to 1.2 mol). Upon addition of 15 % TiC instead of Ti and C, the optimum addition of Sn decreased to 0.7 mol and a higher purity of Ti2SnC was obtained. The Ti2SnC powders were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD).

scholarly journals Potential of Locally Available Clay as Raw Material for Traditional-Ceramic Manufacturing Industries

2012 ◽  
Vol 26 ◽  
pp. 34-37 ◽  
Author(s):  
Adnan Mousharraf ◽  
Md Sazzad Hossain ◽  
Md Fakhrul Islam
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Manufacturing Industries ◽  
Raw Material ◽  
Particle Sizes ◽  
Minimum Level ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naturally Occurring ◽  
Ceramic Manufacturing

The traditional white-ware manufacturing industries in Bangladesh use clay as the prime raw material which is mostly imported from abroad. The main reasons are the lack of proper clay refining technolo gy in the country and in some part the unsuitable chemical and structural composition of the locally available naturally occurring clays. Moreover, particle size has also been identified as a major challenge in processing of naturally available clay. These two vital aspects affect plasticity and strength of clay during their processing. The composition and particle size of locally available clay were investigated using X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) to reveal the potential of these clays for industrial purpose upon refining. XRF analysis showed presence of excess SiO2 content in the form of Silicate, Fe2O3 and TiO2; all of which pose a challenge in the refining process. Moreover the amount of Al2O3 in most of the compositions is also not up to the minimum level. Using the data based on statistics on particle sizes of raw materials of various origins, this experiment was aimed to reveal the composition and properties of locally available clay that can be projected for further refining to make suitable as raw material for whiteware industries. DOI: http://dx.doi.org/10.3329/jce.v26i1.10179 JCE 2011; 26(1): 34-37

Influence of Concentration Modes on Morphology of Nano-Silver

2011 ◽  
Vol 694 ◽  
pp. 284-287 ◽  
Author(s):  
Wei Wei Li ◽  
Lu Hai Li ◽  
Xu Wei Hu ◽  
Hua Fang ◽  
Xian Leng ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Silver Particle ◽  
Particle Sizes ◽  
Silver Particles ◽  
Nano Silver ◽  
Silver Solution ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Sem Test

In order to compare different concentration modes' influence on the nano-silver particle size and morphology,we use three methods to refine nano-silver solution prepared in the lab as:1 centrifugal the solution directly,2 deposit the solution with acetone,3 centrifugal the solution with acetone added.Then test the solution processed with particle size distribution,UV-vis and SEM.The result shows that:the particle sizes of the nano-silver solutions enriched with the three methods are 162.5nm,163.5nm,164nm;the peak of the UV-vis absorption curve are 425nm, 426.5nm,427nm,we can see that different methods of enrichment have less influence on the nano-silver particles' size and morphology. Also the same conclusion can be drawn from SEM test.

Direct manipulation of particle size and morphology of ordered mesoporous silica by flow synthesis

RSC Advances ◽  
2015 ◽  
Vol 5 (18) ◽  
pp. 13331-13340 ◽  
Author(s):  
T. N. Ng ◽  
X. Q. Chen ◽  
K. L. Yeung
Keyword(s):  
Particle Size ◽  
Mesoporous Silica ◽  
Hollow Spheres ◽  
Ordered Mesoporous Silica ◽  
Direct Manipulation ◽  
Flow Synthesis ◽  
Precise Control ◽  
Ordered Mesoporous ◽  
Particle Size And Morphology ◽  
Size And Morphology

Flow-synthesis of mesoporous silica allows deliberate and precise control over the size and shapes and enables the preparation of complex microstructures (i.e., hollow spheres).

scholarly journals Mining Wastes of an Albite Deposit as Raw Materials for Vitrified Mullite Ceramics

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 232
Author(s):  
Pedro J. Sánchez-Soto ◽  
Eduardo Garzón ◽  
Luis Pérez-Villarejo ◽  
George N. Angelopoulos ◽  
Dolores Eliche-Quesada
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Phase Evolution ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Mining Wastes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value

In this work, an examination of mining wastes of an albite deposit in south Spain was carried out using X-ray Fluorescence (XRF), X-ray diffraction (XRD), particle size analysis, thermo-dilatometry and Differential Thermal Analysis (DTA) and Thermogravimetric (TG) analysis, followed by the determination of the main ceramic properties. The albite content in two selected samples was high (65–40 wt. %), accompanied by quartz (25–40 wt. %) and other minor minerals identified by XRD, mainly kaolinite, in agreement with the high content of silica and alumina determined by XRF. The content of Na2O was in the range 5.44–3.09 wt. %, being associated with albite. The iron content was very low (<0.75 wt. %). The kaolinite content in the waste was estimated from ~8 to 32 wt. %. The particle size analysis indicated values of 11–31 wt. % of particles <63 µm. The ceramic properties of fired samples (1000–1350 °C) showed progressive shrinkage by the thermal effect, with water absorption and open porosity almost at zero at 1200–1250 °C. At 1200 °C, the bulk density reached a maximum value of 2.38 g/cm3. An abrupt change in the phase evolution by XRD was found from 1150 to 1200 °C, with the disappearance of albite by melting in accordance with the predictions of the phase diagram SiO2-Al2O3-Na2O and the system albite-quartz. These fired materials contained as main crystalline phases quartz and mullite. Quartz was present in the raw samples and mullite was formed by decomposition of kaolinite. The observation of mullite forming needle-shape crystals was revealed by Scanning Electron Microscopy (SEM). The formation of fully densified and vitrified mullite materials by firing treatments was demonstrated.

Preparation of High-Purity Ultrafine α-Al2O3 by Solid-State Reaction at Room Temperature

2008 ◽  
Vol 368-372 ◽  
pp. 683-685
Author(s):  
Cheng Wei Hao ◽  
Bo Lin Wu ◽  
Ji Yan Li
Keyword(s):  
Solid State ◽  
High Purity ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Raw Materials ◽  
Phase Particle ◽  
Phase Transformation Temperature ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Α Al2o3

Ammonium aluminium carbonate hydroxide (AACH), with a small quantity of γ-AlOOH, was synthesized through solid-state reaction at room temperature using AlCl3·6H2O and NH4HCO3 as raw materials and polyethylene glycol (PEG-10000) as the dispersant. After calcined at 1100°C for 1.5h, α-Al2O3 powders with primary particle sizes of 20~30nm were obtained. The crystal phase, particle size and morphology of the high-purity ultrafine α-Al2O3 were characterized. The results showed that a small quantity of γ-AlOOH in the AACH decomposed and formed crystal seeds. The presence of crystal seeds reduced the nucleation activation energy and therefore reduced the phase transformation temperature.

Magnetic Properties of Bulk Zn0.95-XMnXFe0.05O2 Prepared by Sol-Gel Method and Subsequent Hot Pressing

2011 ◽  
Vol 268-270 ◽  
pp. 356-359 ◽  
Author(s):  
Wen Song Lin ◽  
C. H. Wen ◽  
Liang He
Keyword(s):  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Sol Gel ◽  
Secondary Phase ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Doped Zno

Mn, Fe doped ZnO powders (Zn0.95-xMnxFe0.05O2, x≤0.05) were synthesized by an ameliorated sol-gel method, using Zn(CH3COO)2, Mn(CH3COO)2and FeCl2as the raw materials, with the addition of vitamin C as a kind of chemical reducer. The resulting powder was subsequently compacted under pressure of 10 MPa at the temperature of 873K in vacuum. The crystal structure and magnetic properties of Zn0.95-xMnxFe0.05O2powder and bulk samples have been investigated by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). X-ray photoelectron spectroscopy (XPS) was used to study chemical valence of manganese, iron and zinc in the samples. The x-ray diffraction (XRD) results showed that Zn0.95-xMnxFe0.05O (x≤0.05) samples were single phase with the ZnO-like wurtzite structure. No secondary phase was found in the XRD spectrum. X-ray photoelectron spectroscopy (XPS) showed that Fe and Mn existed in Zn0.95-xMnxFe0.05O2samples in Fe2+and Mn2+states. The results of VSM experiment proved the room temperature ferromagnetic properties (RTFP) of Mn, Fe co-doped ZnO samples.

scholarly journals Dehumidified Air-Assisted Spray-Drying of Cloudy Beetroot Juice at Low Temperature

2021 ◽  
Vol 11 (14) ◽  
pp. 6578
Author(s):  
Aleksandra Jedlińska ◽  
Alicja Barańska ◽  
Dorota Witrowa-Rajchert ◽  
Ewa Ostrowska-Ligęza ◽  
Katarzyna Samborska
Keyword(s):  
Particle Size ◽  
Physicochemical Properties ◽  
Spray Drying ◽  
Low Temperatures ◽  
Beetroot Juice ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Tapped Density ◽  
Lower Loss ◽  
Better Than

This paper discusses the physicochemical properties of powders obtained by spray drying of cloudy beetroot juice, using dehumidified air in variants with or without carriers. The inlet air temperature was 130 °C or 90 °C, and the addition of the carriers was at a ratio of juice to carrier solids of 3:2. In the obtained powders, the following physicochemical properties were determined: water content and water activity, apparent density, loose and tapped density, porosity, flowability, particle size and morphology, and the content and retention of betalains. It was possible to dry cloudy beetroot juice without the use of carriers at low temperatures (90 or 130 °C). The 100% beetroot powders were characterized by satisfactory physicochemical properties, often better than those with carriers (including lower hygroscopicity and higher color saturation and yield). A lower loss of betalains was found for the powders with the addition of carriers. The best process yields were obtained for the powder without carriers at 130 °C and 90 °C.

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