scholarly journals РЕГУЛЮВАННЯ СТІЙКОСТІ РІДКИХ МІКРОСТРУМЕНІВ ПОЛІПРОПІЛЕНУ В МАТРИЦІ СПІВПОЛІАМІДУ ЗА РАХУНОК НАНОДОБАВОК

2021 ◽  
pp. 60-69
Author(s):  
NATALIA REZANOVA ◽  
YURII BUDASH ◽  
VIKTORIIA PLAVAN ◽  
ALLA KORSHUN ◽  
SERHII PRYSTYNSKYI
Keyword(s):  
Aluminum Oxide ◽  
Cross Sections ◽  
Capillary Waves ◽  
Al2o3 Nanoparticles ◽  
Aluminum Oxide Nanoparticles ◽  
Degree Of Dispersion ◽  
The Matrix ◽  
Liquid Microjets ◽  
Kinetics Of ◽  
Instability Coefficient

Goal. Investigation of the effect of the concentration of nanoparticles of aluminum oxide (Al2O3) and alumina modified with silver (Ag/Al2O3) on the decomposition kinetics of liquid microjets of polypropylene (PP) in a copolyamide (CPA) matrix and the possibility of controlling the microfibrillar morphology of the PP/CPA blend.Methodology. The components of the blend were mixed on a screw-disk extruder. The kinetics of the disintegration of liquid microjets was studied using a technique based on the theory of destabilization of a liquid cylinder under the action of capillary waves. The degree of dispersion of polypropylene in the matrix was evaluated by photomicrographs of cross sections of the extrudates of the blends.Results. Nanoadditives of the original and silver-modified aluminum oxide with a content of (0.1 ÷ 3.0) wt.% In the blend increase the compatibility of the components: the surface tension (γαβ) in the compositions of all compositions decreases. Ag/Al2O3 nanoparticles are more effective than aluminum oxide nanoparticles - the γαβ value decreases by 9.6 and 5.3 times, respectively, which ensures a high degree of dispersion of the dispersed phase component in the matrix. The disintegration resistance of polypropylene microjets is increasing, as evidenced by a decrease in the instability coefficient (q) and an increase in the microjet lifetime (tl). The curves of q and tl dependence on the additive content have an extreme character. The minimum values of the instability coefficient of microjets and the maximum values of their lifetime are achieved at a nanoparticle concentration corresponding to the lowest interfacial tension.Scientific novelty. The positive effect of the investigated nanoadditives on the kinetics of the decomposition of liquid microjets of polypropylene in the copolyamide matrix has been established. The highest modifying effect in the presence of Ag/Al2O3 nanoparticles is due to their amphiphilic nature, which ensures the predominant localization of nanoparticles at the interface and a synergistic increase in the degree of compatibility in the PP/CPA system.Practical significance. The regularities of increasing the stability of liquid microjets to disintegration in polymer blends filled with nanoparticles have been established, which will make it possible to determine the parameters of the processes of mixing and forming fibers and films, in which the microfibrillar structure arising during the flow of the melt will remain unchanged in the products.

scholarly journals Вплив добавок нанорозмірного оксиду алюмінію на структуру та реологічні властивості суміші поліпропілен/співполіамід

2020 ◽  
Vol 138 (5) ◽  
pp. 107-114
Author(s):  
Н. М. Резанова ◽  
Ю. О. Будаш ◽  
M. О. Давиденко ◽  
А. В. Ковальчук
Keyword(s):  
Rheological Properties ◽  
Cross Sections ◽  
Average Diameter ◽  
Optical Microscope ◽  
Maximum Effect ◽  
Dispersed Phase ◽  
Al2o3 Nanoparticles ◽  
Aluminum Oxide Nanoparticles ◽  
The Matrix ◽  
Fiber Materials

Investigation of the effect of the concentration of aluminum oxide nanoparticles on the micro- and macro-rheological properties of the melt of a polypropylene / copolyamide (PP / CPA) mixture to control the morphology of nanofilled composites. The starting polymers and nano-additive were melt blended on a worm-disk extruder. The degree of dispersion of the component of the dispersed phase in the matrix was evaluated by micrographs of cross sections of the extrudates of the mixtures. The types of PP structures and their dimensional characteristics were studied using an optical microscope. The effective viscosity of the melts was determined on an MB-2 micro viscometer, and elasticity was calculated as the ratio of the extrudate and die diameters. It is shown that the introduction of a PP / CPA mixture (0.1÷3.0) mass. % Al2O3 nanoparticles makes it possible to control the process of structure formation of the component of the dispersed phase. In this case, the average diameter of PP microfibrils decreases and their mass fraction increases. The maximum effect was achieved when the content of nanoparticles 1.0 mass.%. It has been established that the macro-rheological properties of melts of nanofilled systems are determined by their morphology. The formation of anisotropic structures (PP microfibrils) with smaller diameters causes a decrease in viscosity and an increase in the elasticity of the melts of mixtures, in contrast to similar indicators for PP and CPA. It was shown that Al2O3 nanoparticles do not affect the type of morphology of the thermodynamically incompatible PP / CPA mixture - in nanofilled compositions, as in the initial one, a microfibrillar structure is formed. The modifying effect of nanoadditives is manifested in the formation of a larger number of PP microfibrils and a decrease in their dimensional characteristics. The studied nanoparticle does not interfere with the stable processing of the PP / SPA mixture into fibers and films on extrusion equipment and does not complicate the process of extraction of the matrix polymer from composite extrudates. The introduction of Al2O3 nanoparticles will make it possible to obtain composite products and fine-fiber materials with improved characteristics due to the regulation of phase morphology.

scholarly journals Promoting and Inhibitory Effects of Hydrophilic/Hydrophobic Modified Aluminum Oxide Nanoparticles on Carbon Dioxide Hydrate Formation

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5380
Author(s):  
Yu Liu ◽  
Xiangrui Liao ◽  
Changrui Shi ◽  
Zheng Ling ◽  
Lanlan Jiang
Keyword(s):  
Aluminum Oxide ◽  
Induction Time ◽  
Hydrate Formation ◽  
Equilibrium Temperature ◽  
Greenhouse Gas Mitigation ◽  
Al2o3 Nanoparticles ◽  
Inhibitory Effects ◽  
Aluminum Oxide Nanoparticles ◽  
Experimental Conditions ◽  
Gas Consumption

Hydrate-based CO2 capture from large emission sources is considered a promising process for greenhouse gas mitigation. The addition of nanoparticles may promote or inhibit the formation of hydrates. In this work, CO2 hydrate formation experiments were performed in a dual-cell high-pressure reactor. Non-modified, hydrophilic modified and hydrophobic modified aluminum oxide (Al2O3) nanoparticles at different concentrations were added to assess their promoting or inhibitory effects on CO2 hydrate formation. The equilibrium temperature and pressure, induction time, and total gas consumption during CO2 hydrate formation were measured. The results show that the presence of Al2O3 nanoparticles exerts little effect on the phase equilibrium of CO2 hydrates. Under the experimental conditions, the addition of all Al2O3 nanoparticles imposes an inhibitory effect on the final gas consumption except for the 0.01 wt% addition of hydrophilic modified Al2O3 nanoparticles. The induction time required for the nucleation of CO2 hydrates mainly ranges from 70 to 90 min in the presence of Al2O3 nanoparticles. Compared to the absence of nanoparticles, the addition of non-modified and hydrophilic modified Al2O3 nanoparticle reduces the induction time. However, the hydrophobic modified Al2O3 nanoparticles extend the induction time.

scholarly journals Effect of Aluminum Oxide Nanoparticles Films Thickness on Optical Properties

2018 ◽  
Vol 6 (11) ◽  
Author(s):  
I.H. Hilal ◽  
H. l. Abdullah ◽  
A. M. Ibraheem
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Aluminum Oxide ◽  
Band Gap Energy ◽  
Al2o3 Nanoparticles ◽  
Structural And Optical Properties ◽  
Aluminum Oxide Nanoparticles ◽  
Force Microscopy ◽  
Atomic Force ◽  
Different Thickness

The aluminum oxide (Al2O3) nanoparticles thin  films has been prepared via UV-irradiation methods using metal salts (aluminum nitrate Al(NO3)3) with different  thickness (150 , 200, 300 , and 400) and measuring structural and optical properties. The structure of the (Al2O3) nanoparticles thin films was tested with X-Ray showed that have six main diffraction features corresponding to (111), (311), (222), (400), (511) and (440) planes . The results of atomic force microscopy ( AFM )  indicated that all films have grain size about 25.97-65nm . The optical band gap energy was decreased by the increase of thickness from (5.19-4.68) eV then used aluminum oxide as gas sensor.

scholarly journals The Effects of Using Aluminum Oxide Nanoparticles as Heat Transfer Fillers on Morphology and Thermal Performances of Form-Stable Phase Change Fibrous Membranes Based on Capric–Palmitic–Stearic Acid Ternary Eutectic/Polyacrylonitrile Composite

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1785 ◽  
Author(s):  
Huizhen Ke ◽  
Yonggui Li
Keyword(s):  
Heat Transfer ◽  
Aluminum Oxide ◽  
Stearic Acid ◽  
Phase Change ◽  
Ternary Eutectic ◽  
Stable Phase ◽  
Al2o3 Nanoparticles ◽  
Aluminum Oxide Nanoparticles ◽  
Scanning Calorimetry ◽  
Fibrous Membranes

In this paper, innovative capric–palmitic–stearic acid ternary eutectic/polyacrylonitrile/aluminum oxide (CA–PA–SA/PAN/Al2O3) form-stable phase change composite fibrous membranes (PCCFMs) with different mass ratios of Al2O3 nanoparticles were prepared for thermal energy storage. The influences of Al2O3 nanoparticles on morphology and thermal performances of the form-stable PCCFMs were investigated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and measurement of melting and freezing times, respectively. The results showed that there was no apparent leakage trace from the SEM observation. The DSC analysis indicated that the addition of Al2O3 nanoparticles had no significant effect on phase transition temperatures and enthalpies of the CA–PA–SA/PAN/Al2O3 form-stable PCCFMs. The melting peak temperatures and melting enthalpies of form-stable PCCFMs were about 25 °C and 131–139 kJ/kg, respectively. The melting and freezing times of the CA–PA–SA/PAN/Al2O310 form-stable PCCFMs were shortened by approximately 21% and 23%, respectively, compared with those of the CA–PA–SA/PAN form-stable PCCFMs due to the addition of Al2O3 nanoparticles acting as heat transfer fillers.

Computation in the Analysis of Techno-Economic of the Production of Al2O3 (Aluminum Oxide) Nanoparticles through Precipitation Method

2021 ◽  
Vol 2 (1) ◽  
pp. 65-76
Author(s):  
Yusrianti Sabrina Kurniadianti ◽  
◽  
Adzra Zahra Ziva ◽  
Yuni Kartika Suryana ◽  
Risti Ragadhita ◽  
...  
Keyword(s):  
Economic Evaluation ◽  
Aluminum Oxide ◽  
Net Present Value ◽  
Raw Material ◽  
Industrial Scale ◽  
Precipitation Method ◽  
Al2o3 Nanoparticles ◽  
Present Value ◽  
Aluminum Oxide Nanoparticles ◽  
Evaluation Parameters

This study aims to demonstrate computation in the techno-economic analysis of the production of aluminum oxide (Al2O3) using the precipitation method on an industrial scale. This evaluation is based on the perspective of technical and economic evaluation. Several economic evaluation parameters were analyzed to obtain potential information from the manufacture of Al2O3 nanoparticles based on gross profit margin, payback period, and cumulative net present value. The results of this study identified that the manufacture of Al2O3 nanoparticles using the precipitation method could be done industrially. Based on the engineering perspective, Al2O3 nanoparticles can be produced as much as 6.9 tons and earn an annual profit of 144,635.69 USD with a period of 20 years. To ensure that this project can be carried out, an economic evaluation is made based on estimates of ideal and non-ideal conditions, including tax increases, sales changes, raw material prices, utility prices, and labor’s salary. This study is expected to provide information for the manufacture of Al2O3 nanoparticles using the precipitation method on an industrial scale.

High-resolution observations of metastable γ’ precipitation in Al-15at.%Ag

1996 ◽  
Vol 54 ◽  
pp. 1004-1005
Author(s):  
N. V. Larcher ◽  
I. G. Solorzano
Keyword(s):  
Discontinuous Precipitation ◽  
Equilibrium Phase ◽  
Quantitative Description ◽  
Present Contribution ◽  
Α Phase ◽  
The Matrix ◽  
Aging Sequence ◽  
Matrix Precipitation ◽  
Considerable Detail ◽  
Kinetics Of

It is currently well established that, for an Al-Ag alloy quenched from the α phase and aged within the metastable solvus, the aging sequence is: supersaturated α → GP zones → γ’ → γ (Ag2Al). While GP zones and plate-shaped γ’ are metastable phases, continuously distributed in the matrix, formation of the equilibrium phase γ takes place at grain boundaries by discontinuous precipitation (DP). The crystal structure of both γ’ and γ is hep with the following orientation relationship with respect to the fee α matrix: {0001}γ′,γ // {111}α, <1120>γ′,γ, // <110>α.The mechanisms and kinetics of continuous matrix precipitation (CMP) in dilute Al-Ag alloys have been studied in considerable detail. The quantitative description of DP kinetics, however, has received less attention. The present contribution reports the microstructural evolution resulting from aging an Al-Ag alloy with Ag content higher than those previously reported in the literature, focusing the observations of γ' plate-shaped metastable precipitates.

scholarly journals Continuous Cooling Transformation Behaviour and Bainite Transformation Kinetics of 23CrNi3Mo Carburised Steel

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 48
Author(s):  
Wenjun Song ◽  
Min Lei ◽  
Mingpan Wan ◽  
Chaowen Huang
Keyword(s):  
Phase Transformation ◽  
Volume Fraction ◽  
Austenite Formation ◽  
Steel Matrix ◽  
Transformation Kinetics ◽  
Bainite Transformation ◽  
Continuous Cooling ◽  
The Matrix ◽  
Dimensional Growth ◽  
Kinetics Of

In this study, the phase transformation behaviour of the carburised layer and the matrix of 23CrNi3Mo steel was comparatively investigated by constructing continuous cooling transformation (CCT) diagram, determining the volume fraction of retained austenite (RA) and plotting dilatometric curves. The results indicated that Austenite formation start temperature (Ac1) and Austenite formation finish temperature (Ac3) of the carburised layer decreased compared to the matrix, and the critical cooling rate (0.05 °C/s) of martensite transformation is significantly lower than that (0.8 °C/s) of the matrix. The main products of phase transformation in both the carburised layer and the matrix were martensite and bainite microstructures. Moreover, an increase in carbon content resulted in the formation of lamellar martensite in the carburised layer, whereas the martensite in the matrix was still lath. Furthermore, the volume fraction of RA in the carburised layer was higher than that in the matrix. Moreover, the bainite transformation kinetics of the 23CrNi3Mo steel matrix during the continuous cooling process indicated that the mian mechanism of bainite transformation of the 23CrNi3Mo steel matrix is two-dimensional growth and one-dimensional growth.

Correlations for Interaction Layer Growth in U-Mo/Al Dispersion Fuels

2017 ◽  
Vol 375 ◽  
pp. 29-39
Author(s):  
Boris A. Tarasov ◽  
Stepan N. Nikitin ◽  
Dmitry P. Shornikov ◽  
Maria S. Tarasova ◽  
Igor I. Konovalov
Keyword(s):  
Growth Rate ◽  
Growth Process ◽  
Aluminum Matrix ◽  
Layer Growth ◽  
Radiation Diffusion ◽  
Fission Rate ◽  
Interaction Layer ◽  
The Matrix ◽  
Mechanism And Kinetics ◽  
Kinetics Of

Paper presents the results of the growth rate of the interaction layer of uranium-molybdenum dispersed fuel in aluminum matrix and influence of silicon alloying on it. The growth process of amorphous interaction layer depends on the radiation diffusion which is proportional to the fission rate in the power of 1⁄4. The alloying of the matrix by silicon does not lead to a change in the mechanism and kinetics of the interaction layer growth, but only slows it down.

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