scholarly journals PRODUCTION OF POROUS GLASS-CRYSTALLINE MATERIALS BASED ON GLASS CULLET AND CONVERTER SLAG

2021 ◽  
pp. 20-25
Author(s):  
Yaroslava Koltsova
Keyword(s):  
Porous Glass ◽  
Lightweight Concrete ◽  
Converter Slag ◽  
Average Diameter ◽  
Glass Cullet ◽  
Crystalline Materials ◽  
Temperature Range ◽  
Acicular Structure ◽  
Swelling Coefficient ◽  
The Masses

The study conducted the research aimed to obtaining a porous glass-crystalline materials based on glass cullet and converter slag, which was used as a gas-forming additive. In this work, the chemical and phase compositions of the studied slag were analyzed, and a differential thermal analysis of its sample was carried out. Converter slag was added to the composition of the masses in an amount of 2.5 to 30 wt%, the rest was glass cullet. Вurning of the samples was carried out in the temperature range of 850-925 ° C. For the samples under study, using a sand volumetric meter, the volume was determined and the swelling coefficient was calculated, the compressive strength was determined, and the type of structure, which depends on the average diameter of the prevailing pores, was analyzed. The dependence of the swelling coefficient of the investigated materials on the burdening composition and burning temperature has been established. To obtain porous materials with a swelling coefficient of 2.16-2.67 and uniform fine-porous structure (predominant pore size less than 0.5 mm), it is optimal to introduce converter slag into the composition of the masses in an amount of 10-15 wt%, and the recommended temperature range their burning 850-900 ° C. Analysis of the phase composition of the materials obtained indicates the presence of wollastonite as the main crystalline phase, which, due to the acicular structure of the crystals, has a reinforcing effect and contributes to an increase in strength characteristics. The developed porous glass-crystalline materials can be used as thermal insulation and aggregates in lightweight concrete.

scholarly journals Synthesis of Silicon Nanoparticles in a Novel CO2 Laser Pyrolysis Reactor With an Elongated Reaction Zone

2020 ◽  
Author(s):  
Seok-Ho Maeng ◽  
Hakju Lee ◽  
Seongbeom Kim
Keyword(s):  
Reaction Zone ◽  
Large Scale ◽  
Gas Flow ◽  
Silicon Nanoparticles ◽  
Nanoparticle Synthesis ◽  
Average Diameter ◽  
Laser Pyrolysis ◽  
Pyrolysis Reactor ◽  
The Masses ◽  
Focusing Lens

Abstract We demonstrated silicon nanoparticle synthesis using a novel CO2 laser pyrolysis reactor. The reactor was designed to have an elongated reaction zone more than 10 times longer than conventional laser pyrolysis systems. Such elongation was achieved by aligning the laser beam and precursor gas stream. SiH4 gas was used to synthesize the silicon nanoparticles. The yield of the nanoparticles was 40.9%, as calculated by comparing the masses of the synthesized nanoparticles and precursor gas used. Silicon nanoparticles synthesized by using a typical reactor with identical gas flow rate conditions and without a focusing lens had a nanoparticle yield of 1.7%, which was far smaller than for the new reactor. The average diameter of as-synthesized silicon nanoparticles was 26.7 nm. Considering that high power CO2 lasers are often used for large scale nanoparticle production by laser pyrolysis, our proposed reactor serves as a proof of concept that demonstrates its potential for large scale nanoparticle synthesis.

Thermodynamic Study of Fire-Protective Material

2021 ◽  
Vol 1038 ◽  
pp. 486-491
Author(s):  
Anton Chernukha ◽  
Andrii Chernukha ◽  
Pavlo Kovalov ◽  
Alexander Savchenko
Keyword(s):  
Protective Coating ◽  
Thermal Destruction ◽  
Chemical Processes ◽  
Thermodynamic Study ◽  
Thermodynamic Calculations ◽  
Building Structures ◽  
Protective Material ◽  
Low Speed ◽  
Temperature Range ◽  
Swelling Coefficient

The paper considers the material for the protective coating of building structures made of wood. The possibility of chemical processes occurring in the material leading to its expansion has been studied. The coefficient of expansion of the material when heated is practically established. It has been established that the material can swell, both under the influence of flame and when the temperature rises at a low speed. Swelling coefficient at the same time it reaches 8. The temperature range of swelling is 150–250 С, which is confirmed by thermodynamic calculations and experimentally. The temperature at which the material begins to swell is lower than the temperature of thermal destruction of wood.

scholarly journals Porous aggregate development for lightweight concrete

2020 ◽  
Vol 159 ◽  
pp. 06008
Author(s):  
Olga Miryuk
Keyword(s):  
Liquid Glass ◽  
Multicomponent Mixture ◽  
Lightweight Concrete ◽  
Raw Material ◽  
Structural Defects ◽  
Formation Mechanisms ◽  
Glass Cullet ◽  
Porous Concrete ◽  
Molding Mixture ◽  
Ore Dressing

The article presents the results of studies of a porous aggregate and lightweight concrete obtained using liquid glass and man-made materials (glass cullet, magnetite ore dressing waste, substandard rocks). Feasibility of a multicomponent feed mixture for pyroplastic swelling of granules is substantiated. Optimization of raw mix composition provided the possibility of combining various formation mechanisms of porous granules. A set of technological solutions has been developed aimed at improving the conditions of molding and hardening of raw granules. A method for preparing a raw material mass is proposed that minimizes structural defects of porous granules. Possibility of capacity reaction of a raw mixture due to mechanical activation of solid components and introduction of sodium additives is proved. Technological conditions for low-temperature expansion of a multicomponent mixture and production of porous granules with a density of not more than 300 kg/m3 are determined. The formula of molding mixture for obtaining lightweight concrete using a porous aggregate is proposed. The use of liquid glass as a binder in a concrete mixture is preferred. The temperature of concrete hardening is recommended. The technology of porous concrete developed implements multifunctional properties of liquid glass, provides the use of technogenic materials, saving of energy resources.

Optimization of porous glass chromatography for size-fractionation of bovine casein micelles

1987 ◽  
Vol 54 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Gerald P. McNeill ◽  
William J. Donnelly
Keyword(s):  
Porous Glass ◽  
Volume Fraction ◽  
Skim Milk ◽  
Average Diameter ◽  
Void Volume ◽  
Minimum Size ◽  
Casein Micelles ◽  
Column System ◽  
Milk Casein ◽  
Dual Column

SummaryPermeation chromatography on porous glass was carried out with skim milk at 20 or 30 °C using CPG-10 (50 nm) or a dual column system of CPG-10 (50 nm) followed by CPG-10 (300 nm). On columns of CPG-10 (50 nm) casein micelles were eluted at the void volume and were rapidly and efficiently resolved from non-micellar protein without micelle dissociation. The dual column system resulted in the additional resolution of the micelles into different size ranges. Examination of the resolved micelle fractions by electron microscopy showed a gradual decrease of weight average diameter (Dw) from 228·4 nm in the void volume fraction to 86·3 nm in the smallest micelle fraction. The translucent upper layer of a micelle sediment obtained by ultracentrifugation of skim milk at 30 °C consisted of casein aggregates intermediate in size between monomeric protein and the bulk micelle fraction as shown by its elution behaviour on CPG-10 (50 nm). These aggregates were enriched more than 2-fold with κ-casein relative to skim milk, were devoid of αs2-casein and had an estimated value of Dw of 33 nm. The ultracentrifugate serum contained ∼ 2·5% of total milk casein which had the elution characteristics of monomeric protein on CPG-10 (50 nm). It was concluded that the translucent sediment consisted of the smallest micelle fraction of skim milk and represented the minimum size range for casein polymerization in the natural milk environment. Overall, the results show that porous glass chromatography is an effective and convenient tool for the isolation and study of casein micelles.

Controlled Growth of Germanium Nanowires via a Solid–Liquid–Solid (SLS) Mechanism

2012 ◽  
Vol 557-559 ◽  
pp. 523-529 ◽  
Author(s):  
Shih Fong Lee ◽  
Li Ying Lee ◽  
Yung Ping Chang
Keyword(s):  
Surface Density ◽  
High Surface ◽  
Average Diameter ◽  
Germanium Nanowires ◽  
Temperature Range ◽  
Au Film ◽  
Limited Temperature ◽  
Limited Temperature Range ◽  
Solid Liquid ◽  
Nano Wires

In this study, germanium nanowires (GeNWs) were grown directly on gold-evaporated germanium substrates by a solid-liquid-solid (SLS) mechanism in the temperature range 550°C- 650°C. The growth of GeNWs is very sensitive to the growth temperature and only in a limited temperature range (575°C-625°C) can GeNWs having excellent morphology and high surface density be successfully grown. These long, thin, and straight GeNWs have a high aspect ratio and are surrounded by an oxide layer. The composition of corresponding oxide layers is GeOx (x<2). As the thickness of Au film is decreased from 9 nm to 1 nm, the average diameter of GeNWs decreases from 119.3 nm to 38.5 nm. Our experimental results demonstrate that the diameter of germanium nano¬wires can be controlled by the thickness of Au metal film.

Impact of H3BO3 on Foaming Action of CaCO3 in Borosilicate Foam Glasses

2012 ◽  
Vol 581-582 ◽  
pp. 401-404
Author(s):  
Shu Jiang Liu ◽  
Gui Zhen Fu ◽  
Jian Xing Shen ◽  
Jun Zhang
Keyword(s):  
Pore Size ◽  
Apparent Density ◽  
Average Diameter ◽  
Relative Content ◽  
The Other ◽  
Glass Cullet ◽  
Other Hand

Foam glasses were prepared using borosilicate tube glass cullet along with commercial CaCO3 and H3BO3. The influence of relative content of CaCO3 and H3BO3 on the apparent density, volume and pore size was evaluated. The results show that homogenous microstructures of large pores with the average diameter of 1.0 mm can be obtained by adding small amount of CaCO3 with the aid of 3.0 wt% H3BO3.On the other hand, the foaming effect of CaCO3 is greatly enhanced with increasing H3BO3. However, excess CaCO3 leads to increase of apparent density and decrease of pore size, and the relevant mechanism is discussed.

The Structure and Phase Composition of the Diffusion Zone in a Titanium and Steel Composite

2016 ◽  
Vol 870 ◽  
pp. 214-218 ◽  
Author(s):  
Victor Georgievich Shmorgun ◽  
O.V. Slautin ◽  
Roman Evgenyevich Novikov
Keyword(s):  
Solid Solution ◽  
Phase Composition ◽  
Titanium Carbide ◽  
Diffusion Layer ◽  
Diffusion Zone ◽  
Temperature Range ◽  
Acicular Structure ◽  
Steel Composite ◽  
Steel 20 ◽  
Duration Of Heating

An investigation is performed on the influence of the temperature and duration of heating of the explosively welded titanium ВТ1-0+ Steel 20 composite on the phase composition of the diffusion layer formed at the interface. It is shown that after heating to 800 oС the diffusion layer consists of α + α’-Ti , an iron solid solution in titanium and a decarburized zone. When heated at the temperature range from 900 – 1000 oС, the composition of the diffusion layer is as follows: α + α’-Ti acicular structure, Fe2Ti and FeTi intermetallics, TiC titanium carbide, titanium solid solution in α-Fe and a decarburized zone.

scholarly journals Porous glass ceramic materials with decorative-protective coating

2021 ◽  
pp. 100-106
Author(s):  
Y.I. Koltsova ◽  
◽  
V.I. Ovcharenko ◽  
Keyword(s):  
Ceramic Material ◽  
Protective Coating ◽  
Porous Glass ◽  
Glass Ceramic ◽  
Raw Materials ◽  
Protective Layer ◽  
Glass Ceramic Material ◽  
Glass Cullet ◽  
Waste Products ◽  
Decorative Protective Coating

This study was aimed at producing a porous layered glass ceramic material with a decorative-protective coating via one-stage firing. Waste products were used as gas-forming agents to fabricate a glass ceramic material, which partially solves a problem of their utilization; available natural raw materials were also used as gas-forming agents. A decorative-protective coating was applied simultaneously with the formation of the main layers of the material. It consisted of glass cullet and various amounts of coloring oxide. Firing of the samples was carried out at the temperature of 7500С. The coating containing 99.9 wt.% of glass cullet and 0.1 wt.% of Cr2O3 with the thickness of 425 m and having a greenish color was stated to be the coating of the highest quality. As a result of the research, a three-layer porous glass ceramic material was obtained with a low coefficient of thermal conductivity (0.056 W m–1 K–1). The presence of a fourth front decorative-protective layer will allow using this material in construction as a heat-insulating and structural material without additional cladding.

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