scholarly journals Electrophysical properties of composites based on epoxy resin and carbon fillers

2021 ◽  
Vol 12 (2) ◽  
pp. 104-111
Author(s):  
O. G. Sirenko ◽  
◽  
O. M. Lisova ◽  
S. M. Makhno ◽  
G. M. Gunya ◽  
...  
Keyword(s):  
Particle Size ◽  
Epoxy Resin ◽  
Size Distribution ◽  
Average Particle Size ◽  
Construction Materials ◽  
Expanded Graphite ◽  
Cost Effective ◽  
Average Particle ◽  
Carbon Filler ◽  
Carbon Fillers

Polymeric construction materials based on epoxy resin, carbon fillers, such as graphene nanoplates (GNP), carbon nanotubes (CNT) and fillers of inorganic nature – perlite, vermiculite, sand with improved electrophysical characteristics have been developed. The electrophysical propertieгs of composites obtained in various ways which differ according to the principle of injecting components have been investigated. GNP were obtained in two ways. Size distribution of GNP obtained by electrochemical method is 50 to 150 nm. The average particle size is up to 100 nm. It occurs that these particles tend to aggregate as it is shown by the method of dynamic light scattering. The GNP obtained by dispersing thermally expanded graphite in water in a rotary homogenizer have a particle size distribution of 400 to 800 nm if very small particles and large aggregates are absent. The second method of obtaining GNP is less energy consuming and requires fewer manufacturing cycles, so it is more cost-effective. Obtaining composites using aqueous suspensions of GNP is environmentally friendly. Due to the hydrophobic properties of its surface the electrical conductivity of the system which uses vermiculite is higher than one of that which uses perlite for composites with CNT and GNP. It has been found that the difference of electrophysical characteristics between two systems which contain the same amount of carbon filler is caused by the nature of the surface of dielectric components – sand. By changing the content of dielectric ingredients can expand the functionality of composites if use them for shielding from electromagnetic fields.

Particle Size Distribution of ZrO2:Pr3+ – Influences of pH, High Power Ultrasound, Surfactant and Dopant Quantity

2007 ◽  
Vol 128 ◽  
pp. 97-100 ◽  
Author(s):  
Stephanie Möller ◽  
Janusz D. Fidelus ◽  
Witold Łojkowski
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
High Power ◽  
Average Particle Size ◽  
Sodium Dodecyl ◽  
Average Particle ◽  
Power Ultrasound ◽  
High Power Ultrasound ◽  
Influence Of Ph

The aim of the work was to examine the influence of pH, high power ultrasound, surfactant and dopant quantity on the particle size distribution of ZrO2:Pr3+, with praseodymium content varying between 0.05 and 10 %. The nanopowders were obtained via a hydrothermal microwave driven process. To establish if the dopant was located on the surface of the zirconia nanoparticles, the particle size distribution, as a function of pH, was measured to obtain an estimate of the isoelectric point of the samples. All results indicated that the dopant was concentrated on the surface: the measurements of the particle size distribution show that the pH corresponding to maximum average particle size changes towards higher values when the Pr content increases. Measurements of the particle size distribution dependency on the application of high power ultrasound and the addition of the sodium dodecyl sulphate surfactant show that, under certain conditions, there is a better stabilisation of the nanopowders in a dispersion and undesirable agglomeration is hindered.

Synthesis of Nanostructured Magnetic Mixed-Oxide Ferrite Powders by Using A Novel Chemical Method

2002 ◽  
Vol 720 ◽  
Author(s):  
N N Ghosh
Keyword(s):  
Particle Size ◽  
Mixed Oxide ◽  
Chemical Method ◽  
Average Particle Size ◽  
Cost Effective ◽  
Water Soluble ◽  
Average Particle ◽  
Chemical Route ◽  
Water Soluble Polymer ◽  
Different Temperatures

AbstractIn the present investigation, an attempt has been made to establish a new chemical route for synthesis of the nanostructured mixed oxide ferrite powders. By using this chemical method a variety of ferrite powders having spinel structure and doped with Co, Ni, Mn, Zn etc has been prepared. In this method nitrate salts of the different metals were used as starting materials. The aqueous solutions of the metal nitrates were mixed according to the molar ration of the compositions. Then the mixtures were mixed with an aqueous solution of water soluble polymer (polyvinyl alcohol). This mixture after drying yield fluffy brown powders. These powders were then calcined at different temperatures ranging from 400 °C to 700 °C. Nanostructured powders were obtained from the thermal decomposition of the brown powders. The powders, prepared by calcinations at different temperatures, were characterized by using X-Ray diffraction analysis, IR spectroscopy, TGA/DTA, and TEM. It was observed that the average particle size of the powders are in nanometer scale with a narrow size distribution. The average particle size of the powders was increased with the increase of calcinations temperature.This chemical method has proved to provide a convenient process for the preparation of nanostructured ceramic powders at comparatively low temperatures and offers the potential of being a simple and cost-effective route.

Preparation and Particle Size Characterization of Cu Nanoparticles Prepared by Anodic Arc Plasma

2010 ◽  
Vol 92 ◽  
pp. 163-169
Author(s):  
Hong Xia Qiao ◽  
Zhi Qiang Wei ◽  
Ming Ru Zhou ◽  
Zhong Mao He
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Specific Surface ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Average Particle Size ◽  
Spherical Shape ◽  
Average Particle ◽  
Uniform Size

Copper nanoparticles were successfully prepared in large scales by means of anodic arc discharging plasma method in inert atmosphere. The particle size, specific surface area, crystal structure and morphology of the samples were characterized by X-ray diffraction (XRD), BET equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED). The experiment results indicate that the crystal structure of the samples is fcc structure as same as that of the bulk materials. The specific surface area is is 11 m2/g, with the particle size distribution ranging from 30 to 90 nm, the average particle size about 67nm obtained from TEM and confirmed from XRD and BET results. The nanoparticles have uniform size, higher purity, narrow size distribution and spherical shape can be prepared by this convenient and effective method.

Preparation and Characterization of Gold Nanoparticles in the Presence of Citrate and Soybean Seed Extract in an Acidic Conditions

Drug Research ◽  
2017 ◽  
Vol 67 (05) ◽  
pp. 266-270 ◽  
Author(s):  
Ebrahim Izadi ◽  
Ali Rasooli ◽  
Abolfazl Akbarzadeh ◽  
Soodabeh Davaran
Keyword(s):  
Particle Size ◽  
Gold Nanoparticles ◽  
Size Distribution ◽  
Average Particle Size ◽  
Soybean Seed ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Soybean Extract ◽  
Average Size

AbstractThrough the present study, an eco-friendly method was used to synthesize the gold nanoparticles (GNPs) by using the sodium citrate and extract of the soybean seed as reducing the agents at PH 3. X-Ray diffraction (XRD) method was used to evaluate the crystal structure of as-synthesized NPs and it’s revealed that this method leads to well crystallized GNPs. In order to determine the particle size and their distribution, field emission scanning microscopy (FE-SEM) and dynamic light scattering (DLS) were used. The results showed that, the average particle size distribution of synthesized GNPs in solutions containing of the soybean extract and 1% citrate at PH 3 is about 109.6 and 140.9 nm, respectively. Also, we find that the average size of GNPs is 40 and 33 nm from solutions of citrate and soybean extract, respectively. It was concluded that using the extract of soybean seeds as reducing agent can lead to GNPs with small size and narrow size distribution.

scholarly journals Growth of significantly low dimensional zinc orthotitanate (Zn2TiO4) nanoparticles by solid state reaction method

2018 ◽  
Vol 50 (1) ◽  
pp. 133-138 ◽  
Author(s):  
Lizina Khatua ◽  
Rudrashish Panda ◽  
Avanendra Singh ◽  
Arpan Nayak ◽  
Pravakar Satapathy ◽  
...  
Keyword(s):  
Particle Size ◽  
Solid State ◽  
Surface Area ◽  
Solid State Reaction ◽  
Average Particle Size ◽  
Cost Effective ◽  
Solid State Reaction Method ◽  
Average Particle ◽  
Reaction Method ◽  
Low Dimensional

In this work, the ZnO-TiO2 mixed phase nanoparticles were prepared by solid state reaction method by using ZnO and TiO2 powder as precursors. The X-ray diffraction pattern shows a dominant phase of Zinc Orthotitanate (Zn2TiO4). The average particle size (58?18 nm) calculated by the analysing FESEM data closely matches with the particle size calculated by Scherrer?s equation. The calculated average particle size is significantly smaller than the previously published results of nanoparticles, prepared by same method. In the Brunauer-Emmett-Teller (BET) study the specific surface area of the nanoparticles was found as 8.78 m2/g which is similar to the surface area reported in this material prepared by mechanochemical method. The method which we report is simpler and cost effective unlike the previous reported.

The Influence of Milling Regimes in Beater Mill on Particle Size Distribution and Structural Characteristics of Strontium Hexaferrite Powder

2018 ◽  
Vol 284 ◽  
pp. 158-162
Author(s):  
I.N. Yegorov ◽  
Nikolay Ya. Egorov
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fluidized Bed ◽  
Structural Parameters ◽  
Average Particle Size ◽  
Strontium Hexaferrite ◽  
Average Particle ◽  
Electromagnetic Effect ◽  
Coarse Material

The paper experimentally substantiates effectiveness of method of milling particulate ferromagnetic materials in magneto fluidized bed. Comparative results of particle size distributions and structural parameters of strontium hexaferrite SrFe12O19 powder obtained by milling coarse material in beater mill without electromagnetic effect and in same mill with formation of magneto fluidized bed from mill material are presented. The magneto fluidized bed is formed by constant and alternating gradient magnetic fields with induction lines that are mutually perpendicular and parallel to the plane of rotating beaters. It is shown that application of electromagnetic effect to milling coarse material in beater mill allowed to greatly intensify that process, significantly increase powder quality: increase particle size distribution uniformity and decrease average particle size from 1558.50 μm to 0.56 μm after 120 minutes of processing in the mill. X-ray diffraction analysis showed that milling in beater mill in magneto fluidized bed leads to reduction of coherent-scattering region size, increase of lattice microstrain and dislocation density, making powder more active during sintering process.

Obtaining and Research of Additive Products from Electro-Erosive Cobalt-Chrome Powders

2020 ◽  
Vol 989 ◽  
pp. 801-805
Author(s):  
Evgeniy V. Ageev ◽  
O.G. Loktionova ◽  
A.Y. Altukhov
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Average Particle Size ◽  
Experimental Studies ◽  
Average Particle ◽  
Cobalt Chromium ◽  
Technical Literature ◽  
Specific Particle ◽  
Cobalt Chrome

The main requirement for powders for additive machines is the spherical shape of the particles. Such particles most compactly fit into a certain volume and provide the “fluidity” of the powder composition in the material supply systems with minimal resistance. Based on the peculiarities of the methods of obtaining spherical powders in order to obtain spherical granules of a regulated grain size, the technology of electroerosive dispersion, which is distinguished by relatively low energy costs and ecological cleanliness of the process, is proposed. The main advantage of the proposed technology is the use of waste as raw materials, which is much cheaper than the pure components used in traditional technologies. In addition, this technology is powder, which allows to obtain powder-alloys. The widespread use of the method of EED for the processing of metal waste into powders for the purpose of their reuse and application in additive technologies is hampered by the lack of complete information in the scientific and technical literature on the influence of the original composition, modes and media on the properties of powders and technologies of practical application. Therefore, the development of technologies for the reuse of EED powders and the evaluation of the effectiveness of their use requires the conduct of comprehensive theoretical and experimental studies. The purpose of this work was to obtain and study additive products from electroerosive cobalt-chromium powders of a specific particle size distribution and to study their microstructure. The granulometry of the obtained powders was determined on a laser analyzer of particle sizes “Analysette 22 NanoTec”. The microstructure of additive samples from cobalt-chromium powders (by transverse polishing) was investigated by optical microscopy on an inverted optical microscope OLYMPUS GX51. On the basis of completed studies, aimed at obtaining and studying additive products from electroerosive cobalt-chrome powders of a specific particle size distribution, and studying their microstructure, it was found that additive samples, obtained from a cobalt-chrome powder with an average particle size of 35,68 microns, have practically no pores.

Controlled Growth of Silicon Particles via Plasma Pulsing and their Application as Battery Material

2021 ◽  
Author(s):  
Joseph Schwan ◽  
Brandon Wagner ◽  
Minseok Kim ◽  
Lorenzo Mangolini
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Critical Size ◽  
Coulombic Efficiency ◽  
Plasma Reactor ◽  
Average Particle Size ◽  
Lithium Ion ◽  
Stable Operation ◽  
Average Particle ◽  
Plasma Reactors

Abstract The use of silicon nanoparticles for lithium-ion batteries requires a precise control over both their average size and their size distribution. Particles larger than the generally accepted critical size of 150 nm fail during lithiation because of excessive swelling, while very small particles (<10 nm) inevitably lead to a poor first cycle coulombic efficiency because of their excessive specific surface area. Both mechanisms induce irreversible capacity losses and are detrimental to the anode functionality. In this manuscript we describe a novel approach for enhanced growth of nanoparticles to ~20 nm using low-temperature flow-through plasma reactors via pulsing. Pulsing of the RF power leads to a significant increase in the average particle size, all while maintaining the particles well below the critical size for stable operation in a lithium-ion battery anode. A zero-dimensional aerosol plasma model is used to investigate the dynamics of particle agglomeration and growth in the pulsed plasma reactor. The accelerated growth correlates with the shape of the particle size distribution in the afterglow, which is in turn controlled by parameters such as metastable density, gas and electron temperature. The accelerated agglomeration in each afterglow phase is followed by rapid sintering of the agglomerates into single-crystal particles in the following plasma-on phase. This study highlights the potential of non-thermal plasma reactors for the synthesis of functional nanomaterials, while also underscoring the need for better characterization of their fundamental parameters in transient regimes.

scholarly journals Preparation and Characterization of NiO Nanoparticles by Anodic Arc Plasma Method

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Hongxia Qiao ◽  
Zhiqiang Wei ◽  
Hua Yang ◽  
Lin Zhu ◽  
Xiaoyan Yan
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Specific Surface ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Average Particle Size ◽  
Average Particle ◽  
Arc Plasma ◽  
Nio Nanoparticles

NiO nanoparticles with average particle size of 25 nm were successfully prepared by anodic arc plasma method. The composition, morphology, crystal microstructure, specific surface area, infrared spectra, and particle size distribution of product were analyzed by using X-ray diffraction (XRD), transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED), Fourier transform infrared (FTIR) spectrum, and Brunauer-Emmett-Teller (BET)N2adsorption. The experiment results show that the NiO nanoparticles are bcc structure with spherical shape and well dispersed, the particle size distribution ranging from 15 to 45 nm with the average particle size is about 25 nm, and the specific surface area is 33 m2/g. The infrared absorption band of NiO nanoparticles shows blue shifts compared with that of bulk NiO.

Preparation of Monodispersed and Nano-Sized Spherical SiO2 Particles by Emulsion Method

2004 ◽  
Vol 449-452 ◽  
pp. 1161-1164 ◽  
Author(s):  
Jong Hwa Baek ◽  
Young Soo Kang ◽  
Seog Young Yoon ◽  
Hong Chae Park
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Mixing Time ◽  
Average Particle Size ◽  
Average Particle ◽  
Amorphous Sio2 ◽  
Emulsion Method ◽  
Sio2 Particles ◽  
20 Nm

Spherical nano-sized SiO2 particles have been synthesized from sodium silicate by emulsion method. The influence of emulsifier content and mixing time on the morphology and particle size distribution of the resulting materials was investigated. The characteristics of the obtained SiO2 particles were examined by means of XRD, SEM, TEM, and PSA. The monodispersed shperical SiO2 with the average particle size 20 nm was obtained at a emulsifer content of 3vol% and mixing time of 60 min using ultrasonic disruptor. After calcining at 1200oC for 2 hrs, the amorphous SiO2 transformed wholly to the crystalline cristobalite. As increase in emulsifier content from 1 to 3 vol% did not nearly influence on the morphology of SiO2 particle but slightly changed the particle size distribution. The average particle size of SiO2 decreased significantly from 100 nm to 20 nm with increasing the mixing time.

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