Phase quantification of mullite–zirconia and zircon commercial powders using PAC and XRD techniques

Rapid solidification of Ni-Nb alloys promotes the formation of amorphous structure. Preliminary results indicate promising elastic properties and high fracture strength for the metallic glass. Knowledge of the thermal stability of the amorphus alloy and the changes in properties with temperature is therefore of prime importance. In this work rapidly solidified Ni-Nb alloys were analyzed with transmission electron microscopy (TEM) during in-situ heating experiments and after isothermal annealing of bulk samples. Differential thermal analysis (DTA), scanning electron microscopy (SEM) and x-ray diffraction (XRD) techniques were also used to characterize both the solidification and devitrification sequences.Samples of Ni-44 at.% Nb were electromagnetically levitated, melted, and rapidly solidified by splatquenching between two copper chill plates. The resulting samples were 100 to 200 μm thick discs of 2 to 3 cm diameter. TEM specimens were either ion-milled or alternatively electropolished in a methanol-10% sulphuric acid solution at 20 V and −40°C.

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Analysis of the Pyrolytic Behaviour of Birch, Maple, and Rowan Leaves

Energies ◽

10.3390/en14082091 ◽

2021 ◽

Vol 14 (8) ◽

pp. 2091

Author(s):

Valentina Zubkova ◽

Andrzej Strojwas ◽

Marcin Bielecki

Keyword(s):

Combustion Products ◽

Carbonyl Groups ◽

Chemical Parameters ◽

Chemical Reagents ◽

Urban Greenery ◽

Volatile Products ◽

Different Types ◽

Ft Ir ◽

Xrd Techniques ◽

Lower Contribution

A research study was conducted on the thermal behaviour of leaves of urban greenery (birch, maple, and rowan) and the products of their pyrolysis and extraction as assisted by microwaves. The obtained products of pyrolysis and extraction were investigated with the use of FT-IR and UV spectroscopies and XRD techniques. A contractive analysis of samples of chars, condensates, after-extraction residue, and extracts showed that the changes in structural-chemical parameters of leaves of different types of trees during pyrolysis and extraction take place in distinct ways. About 22% of material was removed from birch leaves during extraction, and more than 17% of material was extracted from maple and rowan leaves. It was determined that, during pyrolysis of after-extraction residue of leaves, many fewer PAH compounds with carbonyl groups along with alcohols and phenols are emitted than during pyrolysis of non-extracted leaves. Taking into account that pyrolysis is the first stage of combustion, a decrease in the amount of dangerous compounds in the volatile products of pyrolysis leads to a lower contribution of such compounds in combustion products. This indicates that leaves of urban greenery can be subjected to combustion after extraction, and the obtained extracts can be used as a source of phytochemicals and chemical reagents.

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Semi-Crystalline Copolymer Hydrogels as Smart Drug Carriers: In Vitro Thermo-Responsive Naproxen Release Study

Pharmaceutics ◽

10.3390/pharmaceutics13020158 ◽

2021 ◽

Vol 13 (2) ◽

pp. 158

Author(s):

Snežana Ilić-Stojanović ◽

Ljubiša Nikolić ◽

Vesna Nikolić ◽

Slobodan Petrović ◽

Violeta Oro ◽

...

Keyword(s):

Drug Carrier ◽

Drug Carriers ◽

Xrd Analysis ◽

Hplc Method ◽

Potential Candidate ◽

Swelling Kinetic ◽

Model Drug ◽

Xrd Techniques ◽

Responsive Hydrogels

In this study, poly(N-isopropylacrylamide-co-2-hydroxypropyl methacrylate) hydrogels were synthesized using free radical initiated copolymerization method. Four hydrogels with different cross-linker concentrations were prepared. Semi-crystalline, cross-linked copolymer networks were confirmed by FTIR, SEM and XRD analysis. Variation of swelling behaviour was monitored gravimetrically and thermo-responsiveness has been noticed. An application of synthesized thermo-responsive hydrogels as carriers for the modulated release of anti-inflammatory model drug was investigated. Moreover, naproxen loading into these hydrogels was also determined using FTIR, SEM and XRD techniques and release was analyzed using HPLC method at simulated physiological conditions. Swelling kinetic and mechanism of water transport, as well as diffusion of naproxen through the hydrogels were analyzed. Thus, the aim of this work was to study various compositions of obtained hydrogels and their possibility of application as a thermo-responsive carrier for prolonged naproxen release in order to evaluate as a potential candidate for drug carrier in future pharmaceutical applications.

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One Step Synthesis and Characterization of Zirconia-Graphene Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.600.174 ◽

2012 ◽

Vol 600 ◽

pp. 174-177 ◽

Cited By ~ 1

Author(s):

Jian Fei Xia ◽

Zong Hua Wang ◽

Yan Zhi Xia ◽

Fei Fei Zhang ◽

Fu Qiang Zhu ◽

...

Keyword(s):

Synthesis And Characterization ◽

Two Dimensional ◽

X Ray Diffraction ◽

X Ray ◽

Graphene Composite ◽

Transmission Electron ◽

One Step ◽

Ft Ir ◽

Xrd Techniques

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.

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Residual Stresses Assessment in Coated Materials: Complementarity between Neutron and X-Ray Techniques

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.465.259 ◽

2011 ◽

Vol 465 ◽

pp. 259-262 ◽

Cited By ~ 1

Author(s):

M. Rogante ◽

Pavol Mikula ◽

Miroslav Vrána

Keyword(s):

Mechanical Tests ◽

Substantial Contribution ◽

Hole Drilling ◽

X Ray Diffraction ◽

Interface Area ◽

X Ray ◽

Coated Materials ◽

Coating Delamination ◽

Yield Trends ◽

Xrd Techniques

The residual stress (RS) status induced in the substrate of coated materials by the coating process plays frequently a major role in lending the component’s characteristics. RS assessment can give, thus, a substantial contribution in justifying different cases of failure or else bad performance of coated components due to e.g. the coating delamination or to other occurrences which are not simply interpretable via the conventional mechanical tests or microstructure analyses. The adoption of both neutron diffraction (ND) and X-ray diffraction (XRD) techniques has revealed its usefulness in assessing the RS values in proximity of the coating interface area, respectively, without any layer removal or hole drilling at the extreme surface. In this paper, some real cases of RS determination in coated materials by using these techniques and exploiting their complementarity are described. ND, in particular, is very suitable for crucial applications, where a much different stress situation than that assessed by XRD could be present at some depth below the surface. The results achieved can yield trends adoptable in monitoring of the coating features.

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Reaction Synthesis and Oxidation Behaviours of Ludwigite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.146-147.475 ◽

2010 ◽

Vol 146-147 ◽

pp. 475-480 ◽

Cited By ~ 1

Author(s):

Ran Liu ◽

Xing Juan Wang ◽

Yong Liang Gao ◽

Qing Lu ◽

Xiang Xin Xue

Keyword(s):

Weight Loss ◽

Mass Loss Rate ◽

Mass Gain ◽

Raw Material ◽

X Ray Diffraction ◽

Blast Furnace Smelting ◽

Isothermal Tg ◽

Lower Temperature ◽

Xrd Techniques ◽

Furnace Smelting

Using ludwigite as raw material, the phase transformation and mass loss rate of ludwigite in the process of oxidizing roasting are investigated by DTA, isothermal TG, scanning electron microscopy (SEM), X-ray diffraction (XRD) techniques. The results showed that magnetite is transformed into hematite, serpentine is decomposed into forsterite at lower temperature (T＜700°C). The weight of ludwigite has a small loss below 600°C. The decomposed of szaibelyite dehydrated and formed into suanite about 700°Cis the main reason of causing ludwigite mass losses. By comparing the curves of ludwigite at different temperature from 700 to 900°C, the process of oxidizing roasting can be divided into three phases: characterized by a period of fast weight loss, and then followed by a mass gain. Finally, weight of sample is no longer change with prolongation of time. The final weight loss is 6.062%, 6.658% and 7.442% respectively for test temperature. Suanite can not be decomposed to form B2O3 and volatilized when the temperature of oxidizing roasting is below 1142 °C. It is found by XRD that paigeite and magnoferrite are the most stable composition without deterioration on oxidizing roasting. The experiment results can provide theoretical references for agglomeration and blast furnace smelting of ludwigite.

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Polymer-graphene composites by photocuring of a system containing benzophenone macromer

Journal of the Serbian Chemical Society ◽

10.2298/jsc151218040j ◽

2016 ◽

Vol 81 (9) ◽

pp. 1055-1068

Author(s):

Florentina Jitaru ◽

Andreea Chibac ◽

George Epurescu ◽

Ioana Ion ◽

Tinca Buruiana

Keyword(s):

Graphene Oxide ◽

Hybrid Composites ◽

Two Photon ◽

Polymerization Kinetic ◽

Composites Materials ◽

Femtosecond Laser Beam ◽

Reduced Graphene ◽

Direct Laser ◽

Xrd Techniques ◽

Graphene Structures

Formulations incorporating benzophenone oligodimethacrylate (BP-DMA) and graphene structures (graphene oxide/GO, reduced graphene oxide/RGO) were exposed to UV/vis irradiation or femtosecond laser beam to achieve hybrid composites. All structures were characterized through various methods including 1H NMR and FTIR spectroscopies, optical microscopy, TEM, SEM/EDAX analysis, and DSC/XRD techniques. The photopolymerization of BP-DMA in monomer compositions with and without GO or RGO was investigated by photo-DSC and FTIR methods for determining the polymerization kinetic parameters. The photopolymerization experiments revealed a good photoreactivity of the monomers (degree of conversion: 65-77%) after 1 minute exposure to UV/vis irradiation and the addition of graphene (up to 0.5%), whereas the polymerization rate varied between 0.14 and 0.1 s-1. Moreover, two-photon photopolymerization of the formulations in presence/absence of GO or RGO nanosheets (0.1 wt.%) generated 2D microstructures by direct laser writing procedure. Also, the morphology and the properties of composites materials were analyzed.

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Synthesis of (Bi,Pb)-2223 superconductor powder by pechini method

Revista Brasileira de Física Tecnológica Aplicada ◽

10.3895/rbfta.v5n1.7550 ◽

2018 ◽

Vol 5 (1) ◽

Author(s):

Guilherme Botega Torsoni ◽

Cícero Rafael Cena ◽

Gustavo Quereza de Freitas ◽

Claudio Luis Carvalho

Keyword(s):

Pechini Method ◽

Crystallization Kinetic ◽

Inorganic Ions ◽

Precursor Solution ◽

X Ray Diffraction ◽

High Concentration ◽

Powder Morphology ◽

Chemical Reagents ◽

Different Temperatures ◽

Xrd Techniques

In this paper, we present a detailed route of synthesis to produce ceramic superconductor Bi1,6Pb0,4Sr2Ca2Cu3Ox (Bi,Pb)-2223 powder by Pechini method. The obtained polymeric precursor solution was produced by using inexpensive chemical reagents, which showed a great stability for three weeks with high concentration of BPSCCO inorganic ions. The crystallization kinetic of BPSCCO powder was investigated by thermal analysis (DSC/TGA) and X-ray diffraction (XRD) techniques. The thermal treatment of the BPSCCO powder at different temperatures showed that complex phase equilibrium occurs to the system. The three superconductor phases seems to coexist in a large range of temperature, the Bi-2201 phase was crystallized around 500 oC and then, after 840 oC the desirable (Bi,Pb)-2223 phase appears with coexistence of the Bi-2212 phase at low quantity. Finally, the powder morphology was characterized by scanning electron microscopy (SEM), the results point to a typical plate like formation of the grains.

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Electrorefining of aluminum alloy in ionic liquids at low temperatures

Journal of Mining and Metallurgy Section B Metallurgy ◽

10.2298/jmmb0302043k ◽

2003 ◽

Vol 39 (1-2) ◽

pp. 43-58 ◽

Cited By ~ 19

Author(s):

V. Kamavaram ◽

D. Mantha ◽

R.G. Reddy

Keyword(s):

Aluminum Alloy ◽

Ionic Liquids ◽

Energy Consumption ◽

Low Temperatures ◽

Cell Voltage ◽

Liquid Electrolyte ◽

X Ray ◽

Ionic Liquid Electrolyte ◽

Anhydrous Alcl3 ◽

Xrd Techniques

The electrorefining of aluminum alloy (A360) in ionic liquids at low temperatures has been investigated. The ionic liquid electrolyte was prepared by mixing anhydrous AlCl3 and 1-Butyl-3- methylimidazolium chloride (BMIC) in appropriate proportions. The effect of the cell voltage temperature, and the composition of the electrolyte on the electrorefining process has been studied. The characterization of the deposited aluminum was performed using scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The influence of experimental parameters such as cell voltage and concentration of AlCl3 in the electrolyte on the deposit morphology was discussed. The composition of the aluminum deposits was analyzed using X-ray fluorescence spectrometer (XRF). Aluminum deposits with purity higher than 99.89 % were obtained. At a cell voltage of 1.0 V vs. Al/Al(III), the energy consumption was about 3 kWh/kg-Al. The main advantage of the process is low energy consumption compared to the existing industrial aluminum refining process.

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