Nanostructured Polymetallic Powders to Create New Functional Materials on its Base

2015 ◽  
Vol 670 ◽  
pp. 49-54 ◽  
Author(s):  
Yuriy A. Zaharov ◽  
Valeriy M. Pugachev ◽  
Kseniya A. Datiy ◽  
Anna N. Popova ◽  
Anastasiya S. Valnyukova ◽  
...  
Keyword(s):  
Particle Size ◽  
Phase Diagrams ◽  
Spatial Organization ◽  
Functional Materials ◽  
Particle Morphology ◽  
Cloud Type ◽  
Synthesis Conditions ◽  
Micron Size ◽  
Common Nature ◽  
20 Nm

In the paper, the particle morphology is considered and the slices of phase diagrams of nanosystems agreeable to the synthesis conditions are constructed according to the data obtained earlier by authors, as well as new results of the study of nanostructured Fe-Co, Fe-Ni, Co-Ni, Fe-Co-Ni, Fe-Pt, Cu-Ni and Ni-Cd powders. It is found that all considered polymetallic systems have common nature of the particle size spatial organization, i.e., 7-20 nm nanocrystals (for different systems) form highly compact aggregates (40-100 nm) which put together into loose porous agglomerates (up to 200-250 nm) and then into unconsolidated micron size formation of cloud type. It is classified uncovered features of nanostructured polymetallic phase diagrams in comparison with phase diagrams of bulk systems. Magnetic properties of nanosystems are studied.

Synthesis and Structure of Ultrafine Zeolite KL (LTL) Crystallites and their Use for Thin Film Zeolite Processing

1994 ◽  
Vol 371 ◽  
Author(s):  
Michael Tsapatsis ◽  
Tatsuya Okubo ◽  
Mark Lovallo ◽  
Mark E. Davis
Keyword(s):  
Thin Film ◽  
Particle Size ◽  
Colloidal Suspensions ◽  
Particle Sizes ◽  
Synthesis Conditions ◽  
Zeolite Particle ◽  
Water Ph ◽  
20 Nm

AbstractSynthesis conditions were identified leading to agglomerates of nearly cylindrical zeolite nanocrystals with dimensions less than 50 nm in the channel direction and approximately 10 nm in diameter (in the direction perpendicular to the zeolite channels). The nanocrystals form agglomerates with approximate particle sizes ranging from 20 to 400 nm as determined by DLS. Washing with repeated centrifugation and sonication results in stable (over long periods of time) colloidal suspensions of the zeolite particles in water (pH ∼ 7) with zeolite concentrations of lOg/l. The average zeolite particle size of the suspension can be as low as 20 nm as determined by DLS. Films free of microcracks were prepared from these suspensions by evaporation of water.

Materials Interaction in Cofired Platinum /Alumina High Density Feedthrough for Implantable Applications

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000557-000562
Author(s):  
Ali Karbasi ◽  
W. Kinzy Jones
Keyword(s):  
Particle Size ◽  
Thermal Expansion ◽  
Melting Point ◽  
Exothermic Reaction ◽  
Particle Morphology ◽  
High Density ◽  
X Ray Diffraction ◽  
X Ray ◽  
Micron Size ◽  
Effect Of Particle Size

Neurostimulator applications will require much higher I/O feedthrough density for hermetic implantable enclosures, often greater than 100 I/O. This work evaluates the development of high-density platinum via structure cofired in alumina. The platinum was observed to melt when cofired at 1550°C, almost 200°C below its melting point, independent of the particle size (nano to micron size particles) or particle morphology. An analysis of the effect of particle size (nano to micron size Pt), firing atmosphere (air, hydrogen, inert), firing temperatures, intermetallic reactions and additives to control thermal expansion and adhesion strength was performed to evaluate and minimize this exothermic reaction. The interaction of platinum and alumina has been evaluated using X-ray diffraction and SEM.

Materials Interaction in Cofired Platinum /Alumina High Density Feedthrough for Implantable Neurostimulator Applications

2011 ◽  
Vol 2011 (1) ◽  
pp. 000534-000538
Author(s):  
Ali Karbasi ◽  
W. Kinzy Jones
Keyword(s):  
Particle Size ◽  
Thermal Expansion ◽  
Melting Point ◽  
Exothermic Reaction ◽  
Particle Morphology ◽  
High Density ◽  
X Ray Diffraction ◽  
X Ray ◽  
Micron Size ◽  
Effect Of Particle Size

Neurostimulator applications will require much higher I/O feedthrough density for hermetic implantable enclosures, often greater than 100 I/O. This work evaluates the development of high-density platinum via structure cofired in alumina. The platinum was observed to melt when cofired at 1550°C, almost 200°C below its melting point, independent of the particle size (nano to micron size particles) or particle morphology. An analysis of the effect of particle size (nano to micron size Pt), firing atmosphere (air, hydrogen, inert), firing temperatures, intermetallic reactions and additives to control thermal expansion and adhesion strength was performed to evaluate and minimize this exothermic reaction. The interaction of platinum and alumina has been evaluated using X-ray diffraction and SEM.

Surface energy of cellulosic materials: The effect of particle morphology, particle size, and hydroxyl number

TAPPI Journal ◽  
2015 ◽  
Vol 14 (9) ◽  
pp. 565-576 ◽  
Author(s):  
YUCHENG PENG ◽  
DOUGLAS J. GARDNER
Keyword(s):  
Particle Size ◽  
Surface Energy ◽  
Particle Morphology ◽  
Nanofibrillated Cellulose ◽  
Particle Sizes ◽  
Hydroxyl Number ◽  
Small Individual ◽  
Dispersion Component ◽  
Commercial Applications ◽  
Lower Temperature

Understanding the surface properties of cellulose materials is important for proper commercial applications. The effect of particle size, particle morphology, and hydroxyl number on the surface energy of three microcrystalline cellulose (MCC) preparations and one nanofibrillated cellulose (NFC) preparation were investigated using inverse gas chromatography at column temperatures ranging from 30ºC to 60ºC. The mean particle sizes for the three MCC samples and the NFC sample were 120.1, 62.3, 13.9, and 9.3 μm. The corresponding dispersion components of surface energy at 30°C were 55.7 ± 0.1, 59.7 ± 1.3, 71.7 ± 1.0, and 57.4 ± 0.3 mJ/m2. MCC samples are agglomerates of small individual cellulose particles. The different particle sizes and morphologies of the three MCC samples resulted in various hydroxyl numbers, which in turn affected their dispersion component of surface energy. Cellulose samples exhibiting a higher hydroxyl number have a higher dispersion component of surface energy. The dispersion component of surface energy of all the cellulose samples decreased linearly with increasing temperature. MCC samples with larger agglomerates had a lower temperature coefficient of dispersion component of surface energy.

The effect of Tin additionon on Structural and magnetic properties of the stannoferrite Li0.5+0.5XFe2.5-1.5XSnXO4

2016 ◽  
Vol 12 (3) ◽  
pp. 4307-4321 ◽  
Author(s):  
Ahmed Hassan Ibrahim ◽  
Yehia Abbas
Keyword(s):  
Particle Size ◽  
Fine Particles ◽  
Magnetic Moments ◽  
Lithium Ferrite ◽  
Tem Analysis ◽  
Weiss Temperature ◽  
X Ray ◽  
Two Phases ◽  
Nanocrystalline Ferrite ◽  
20 Nm

The physical properties of ferrites are verysensitive to microstructure, which in turn critically dependson the manufacturing process.Nanocrystalline Lithium Stannoferrite system Li0.5+0.5XFe2.5-1.5XSnXO4,X= (0, 0.2, 0.4, 0.6, 0.8 and 1.0) fine particles were successfully prepared by double sintering ceramic technique at pre-sintering temperature of 500oC for 3 h andthepre-sintered material was crushed and sintered finally in air at 1000oC.The structural and microstructural evolutions of the nanophase have been studied using X-ray powder diffraction (XRD) and the Rietveld method.The refinement results showed that the nanocrystalline ferrite has a two phases of ordered and disordered phases for polymorphous lithium Stannoferrite.The particle size of as obtained samples were found to be ~20 nm through TEM that increases up to ~ 85 nmand isdependent on the annealing temperature. TEM micrograph reveals that the grains of sample are spherical in shape. (TEM) analysis confirmed the X-ray results.The particle size of stannic substituted lithium ferrite fine particle obtained from the XRD using Scherrer equation.Magneticmeasurements obtained from lake shore’s vibrating sample magnetometer (VSM), saturation magnetization ofordered LiFe5O8 was found to be (57.829 emu/g) which was lower than disordered LiFe5O8(62.848 emu/g).Theinterplay between superexchange interactions of Fe3+ ions at A and B sublattices gives rise to ferrimagnetic ordering of magnetic moments,with a high Curie-Weiss temperature (TCW ~ 900 K).

Optimization of the Preparation Process of Nano-TiO2/Micro-Cu Composite Particles

2010 ◽  
Vol 105-106 ◽  
pp. 492-494 ◽  
Author(s):  
Bin Wang ◽  
Hai Ping Cui ◽  
Jun Yan ◽  
Shi Guo Du
Keyword(s):  
Particle Morphology ◽  
Oxide Semiconductor ◽  
Photon Absorption ◽  
Composite Particles ◽  
Preparation Process ◽  
Nano Tio2 ◽  
Surface Design ◽  
Acidic Aqueous Solution ◽  
Micron Size ◽  
Hydrolysis Of

Nano-TiO2/micro-Cu composite particles were prepared by hydrolysis of Ti(OBu)4 in abundant acidic aqueous solution and subsequent reflux in the presence of micron size Cu powders. The preparation process was optimized using response surface design with the degradation of TiO2/Cu particles to Methyl orange as target. The particle morphology and composition were characterized by FE-SEM, XPS and XRD. The photon absorption properties of composite particles was investigated by the UV-VIS DRS experiments, and the results show the photoabsorption property of composite particles is intermediate between TiO2 particles and Cu powders, showing cooperative effect by the combination of oxide semiconductor particles with metal substrate.

INFLUENCE OF METAL POWDER PRODUCTION METHOD ON MICROSTRUCTURE AND FLUIDITY OF MAGNETICALLY ALLOY GRANULATE

2021 ◽  
Vol 2021 (9) ◽  
pp. 3-7
Author(s):  
Dmitriy Kostin ◽  
Aleksandr Amosov ◽  
Anatoliy Samboruk ◽  
Bogdan Chernyshev ◽  
Anton Kamynin
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Comparative Studies ◽  
Particle Morphology ◽  
Production Method ◽  
Magnetic Alloy ◽  
Gas Atomization ◽  
Metal Powders ◽  
Hard Magnetic Alloy

A comparison is made of the characteristics of metal powders of a hard magnetic alloy produced by centrifugal spraying and gas atomization. Comparative studies of particle morphology and particle size distribution of powders are presented in order to determine them.

scholarly journals Particle Morphology Analysis of Biomass Material Based on Improved Image Processing Method

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Zhaolin Lu ◽  
Xiaojuan Hu ◽  
Yao Lu
Keyword(s):  
Image Processing ◽  
Particle Size ◽  
Particle Morphology ◽  
Processing Method ◽  
Image Resolution ◽  
Ultrasonic Dispersion ◽  
Image Processing Method ◽  
Size And Shape ◽  
Nominal Size ◽  
Particle Size And Shape

Particle morphology, including size and shape, is an important factor that significantly influences the physical and chemical properties of biomass material. Based on image processing technology, a method was developed to process sample images, measure particle dimensions, and analyse the particle size and shape distributions of knife-milled wheat straw, which had been preclassified into five nominal size groups using mechanical sieving approach. Considering the great variation of particle size from micrometer to millimeter, the powders greater than 250 μm were photographed by a flatbed scanner without zoom function, and the others were photographed using a scanning electron microscopy (SEM) with high-image resolution. Actual imaging tests confirmed the excellent effect of backscattered electron (BSE) imaging mode of SEM. Particle aggregation is an important factor that affects the recognition accuracy of the image processing method. In sample preparation, the singulated arrangement and ultrasonic dispersion methods were used to separate powders into particles that were larger and smaller than the nominal size of 250 μm. In addition, an image segmentation algorithm based on particle geometrical information was proposed to recognise the finer clustered powders. Experimental results demonstrated that the improved image processing method was suitable to analyse the particle size and shape distributions of ground biomass materials and solve the size inconsistencies in sieving analysis.

Effect of the Synthesis Method on the Properties of Ultrafine YAG Powder

2018 ◽  
Vol 281 ◽  
pp. 40-45
Author(s):  
Jie Guang Song ◽  
Lin Chen ◽  
Cai Liang Pang ◽  
Jia Zhang ◽  
Xian Zhong Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Hydrothermal Reaction ◽  
Synthesis Method ◽  
Particle Morphology ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Synthesis Process ◽  
Powder Materials ◽  
Co Precipitation

YAG materials has a number of unique properties, the application is very extensive. In this paper, the superfine YAG powder materials were prepared by co-precipitation method and hydrothermal precipitation method. The influence of synthesis process on the morphology of the powder was investigated. The results showed that the precursor powder prepared via the co-precipitation method is mainly from amorphous to crystalline transition with the increasing calcination temperature, the precursor agglomeration is more serious, In the process of increasing the calcination temperature, the dispersibility of the roasted powder is greatly improved, which is favorable for the growth of the crystal grains, so that the particle size of the powder is gradually increased, the YAG precursor prepared by the co-precipitation method is transformed into YAG crystals, the phase transition occurs mainly between 900 and 1100°C. When the molar ratio of salt to alkali is Y3+: OH-=1: 8 via the hydrothermal reaction, the YAG particles with homogeneous morphology can be obtained. When the molar ratio of salt and alkali is increased continuously, the morphology of YAG particles is not obviously changed. The co-precipitation method is easy to control the particle size, the hydrothermal method is easy to control the particle morphology.

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