Thermal Stability and Kinetics of Formation of Magnesium Oxychloride Phase 3Mg(OH)2∙MgCl2∙8H2O

In this paper, magnesium oxychloride cement with stoichiometry 3Mg(OH)2∙MgCl2∙8H2O (MOC 3-1-8) was prepared and characterized. The phase composition and kinetics of formation were studied by X-ray diffraction (XRD) and Rietveld analysis of obtained diffractograms. The chemical composition was analyzed using X-ray fluorescence (XRF) and energy dispersive spectroscopy (EDS). Furthermore, scanning electron microscopy (SEM) was used to study morphology, and Fourier Transform Infrared (FT-IR) spectroscopy was also used for the analysis of the prepared sample. In addition, thermal stability was tested using simultaneous thermal analysis (STA) combined with mass spectroscopy (MS). The obtained data gave evidence of the fast formation of MOC 3-1-8, which started to precipitate rapidly. As the length of the time of ripening increased, the amount of MgO decreased, while the amount of MOC 3-1-8 increased. The fast formation of the MOC 3-1-8 phase at an ambient temperature is important for its application in the production of low-energy construction materials, which corresponds with the challenges of a sustainable building industry.

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Magnesium Oxybromides MOB-318 and MOB-518: Brominated Analogues of Magnesium Oxychlorides

Applied Sciences ◽

10.3390/app10114032 ◽

2020 ◽

Vol 10 (11) ◽

pp. 4032

Author(s):

Anna-Marie Lauermannová ◽

Michal Lojka ◽

Filip Antončík ◽

David Sedmidubský ◽

Milena Pavlíková ◽

...

Keyword(s):

Building Materials ◽

Simultaneous Thermal Analysis ◽

Heating Process ◽

X Ray Diffraction ◽

Sustainable Building ◽

X Ray ◽

Environmentally Sustainable ◽

Transmission Electron ◽

Magnesium Oxychloride ◽

Sustainable Building Materials

The search for environmentally sustainable building materials is currently experiencing significant expansion. It is increasingly important to find new materials or reintroduce those that have been set aside to find a good replacement for Portland cement, which is widely used despite being environmentally insufficient and energy-intensive. Magnesium oxybromides, analogues to well-known magnesium oxychloride cements, fit both categories of new and reintroduced materials. In this contribution, two magnesium oxybromide phases were prepared and thoroughly analyzed. The stoichiometries of the prepared phases were 5Mg(OH)2∙MgBr2∙8H2O and 3Mg(OH)2∙MgBr2∙8H2O. The phase analysis was determined using X-ray diffraction. The morphology was analyzed with scanning and transmission electron microscopy. The chemical composition was studied using X-ray fluorescence and energy dispersive spectroscopy. Fourier transform infrared spectroscopy was also used. The thermal stability and the mechanism of the release of gasses linked to the heating process, such as water and hydrobromic acid evaporation, were analyzed using simultaneous thermal analysis combined with mass spectroscopy. The obtained results were compared with the data available for magnesium oxychlorides.

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Thermodynamic Properties of Stoichiometric Non-Superconducting Phase Y2BaCuO5

Materials ◽

10.3390/ma12193163 ◽

2019 ◽

Vol 12 (19) ◽

pp. 3163

Author(s):

Filip Antončík ◽

David Sedmidubský ◽

Adéla Jiříčková ◽

Michal Lojka ◽

Tomáš Hlásek ◽

...

Keyword(s):

Thermodynamic Properties ◽

High Temperature Superconductor ◽

Simultaneous Thermal Analysis ◽

Rietveld Analysis ◽

Drop Calorimetry ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

X Ray ◽

Green Coloration ◽

Ab Initio Dft

Y2BaCuO5 often occurs as an accompanying phase of the well-known high-temperature superconductor YBa2Cu3O7 (also known as YBCO). Y2BaCuO5, easily identifiable due to its characteristic green coloration, is often referred to as ‘green phase’ or ‘Y-211’. In this contribution, Y2BaCuO5 phase was studied in detail with a focus on its thermal and thermodynamic properties. Energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were employed in the study of sample’s morphology and chemical composition. XRD data were further analyzed and lattice parameters refined by Rietveld analysis. Simultaneous thermal analysis was employed to study thermal stability. Particle size distribution was analyzed by laser diffraction. Finally, thermodynamic properties, namely heat capacity and relative enthalpy, were measured by drop calorimetry, differential scanning calorimetry (DSC), and physical properties measurement system (PPMS). Enthalpy of formation was assessed from ab-initio DFT calculations.

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An x-ray diffraction study of the kinetics of formation of barium-calcium aluminates and tungstates

Journal of Structural Chemistry ◽

10.1007/bf00738934 ◽

1960 ◽

Vol 1 (2) ◽

pp. 163-167 ◽

Cited By ~ 3

Author(s):

A. A. Maklakov ◽

E. P. Ostapchenko

Keyword(s):

Diffraction Study ◽

X Ray Diffraction ◽

X Ray ◽

Calcium Aluminates ◽

Kinetics Of Formation ◽

Kinetics Of

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SINTESIS DAN KARAKTERISASI FAUJASIT DARI ABU LAYANG : Kajian Pengaruh Waktu Sintesis Terhadap Stabilitas Termal Struktur Faujasit (Kinetics of Faujasite Formation from Fly Ash)

Sains & Teknologi ◽

10.24123/jst.v2i2.2249 ◽

2019 ◽

Vol 2 (2) ◽

pp. 10

Author(s):

Sutarno Sutarno ◽

Arief Budyantoro

Keyword(s):

Thermal Stability ◽

Fly Ash ◽

Amorphous Phase ◽

Zeolite Y ◽

Weight Ratio ◽

Hydrothermal Time ◽

X Ray Diffraction ◽

X Ray ◽

Kinetics Of ◽

Thermal Stability Of

Faujasite was hydrothermally synthesized from fly ash at 100oC in alkaline solution by reflux with 5M HCl and fusion with NaOH (weight ratio of NaOH/fly ash = 1.2) pretreatments. Kinetics of faujasite formation was performed by variation of hydrothermal time (0-120 hours). Thermal stability of faujasite from fly ash was tested at 400-900oC and was compared with commercial zeolite Y. The solid products were characterized by X-ray diffraction method. Results showed that faujasite was formed through dissolution of fly ash components such as quartz, mullite and amorphous aluminosilicates (0-3 hours) followed by crystallization to form faujasite (6-48 hours). In longer hydrothermal time (48-72 hours), faujasite transformed into zeolite P and completely formed hydroxysodalite after 120 hours. X-ray diffraction pattern showed that thermal stability of faujasite from fly ash was relatively lower than that of commercial zeolite Y. Faujasite from fly ash transformed into amorphous phase at 800oC whereas commercial zeolite Y transformed into amorphous phase at 900oC.

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Dynamic x-ray diffraction and nanosecond quantification of kinetics of formation of β -zirconium under shock compression

Physical Review B ◽

10.1103/physrevb.102.060101 ◽

2020 ◽

Vol 102 (6) ◽

Author(s):

Patricia Kalita ◽

Justin Brown ◽

Paul Specht ◽

Seth Root ◽

Melanie White ◽

...

Keyword(s):

Shock Compression ◽

X Ray Diffraction ◽

X Ray ◽

Kinetics Of Formation ◽

Kinetics Of

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In situ studies on the kinetics of formation and crystal structure of In4Sn3O12 using high-energy x-ray diffraction

Journal of Applied Physics ◽

10.1063/1.2969913 ◽

2008 ◽

Vol 104 (4) ◽

pp. 043520 ◽

Cited By ~ 12

Author(s):

G. B. González ◽

J. S. Okasinski ◽

T. O. Mason ◽

T. Buslaps ◽

V. Honkimäki

Keyword(s):

Crystal Structure ◽

High Energy ◽

X Ray Diffraction ◽

X Ray ◽

In Situ Studies ◽

Kinetics Of Formation ◽

Kinetics Of

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Surface and Bulk Crystallization Kinetics of Er3+ Doped Mixed Alkali Phosphate Glasses

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.146-147.1142 ◽

2010 ◽

Vol 146-147 ◽

pp. 1142-1146

Author(s):

Yong Zheng Fang ◽

Jia Yue Xu ◽

Zhang Yong Wang ◽

Hui Chun Qian

Keyword(s):

Thermal Stability ◽

Particle Size ◽

Phosphate Glasses ◽

X Ray Diffraction ◽

X Ray ◽

Bulk Crystallization ◽

Dsc Measurements ◽

Mixed Alkali ◽

Kinetics Of ◽

Dsc Curves

DSC measurements have been carried out for the as-quenched xNa2O- (15-x)Li2O-4B2O3-11Al2O3-5BaO-65P2O5 (x=0,3.75,7.5,11.25 and 15 mol%) glasses with different particle size. Two crystallization peaks appear on the DSC curves for sample sized 90-110μm. The presence of two crystallization peaks is due to different crystallization mechanisms, surface and bulk (internal) crystallization. The X-ray diffraction measurements are also employed to investigate the crystallization of glasses. The results show that bulk crystallization is difficult to occur in the studied phosphate glasses. The effect of mixed alkali on glass thermal stability is also studied in this paper. The surface and bulk crystallization active energies are calculated according to Kissinger equation.

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Carbon Dioxide Uptake by MOC-Based Materials

Applied Sciences ◽

10.3390/app10072254 ◽

2020 ◽

Vol 10 (7) ◽

pp. 2254 ◽

Cited By ~ 4

Author(s):

Ondřej Jankovský ◽

Michal Lojka ◽

Anna-Marie Lauermannová ◽

Filip Antončík ◽

Milena Pavlíková ◽

...

Keyword(s):

Carbon Dioxide ◽

Building Materials ◽

Rietveld Analysis ◽

Co2 Uptake ◽

X Ray Diffraction ◽

Carbon Footprints ◽

Carbon Dioxide Uptake ◽

Magnesium Oxychloride ◽

Kinetics Of ◽

Harmful Effects

In this work, carbon dioxide uptake by magnesium oxychloride cement (MOC) based materials is described. Both thermodynamically stable magnesium oxychloride phases with stoichiometry 3Mg(OH)2∙MgCl2∙8H2O (Phase 3) and 5Mg(OH)2∙MgCl2∙8H2O (Phase 5) were prepared. X-ray diffraction (XRD) measurements were performed to confirm the purity of the studied phases after 7, 50, 100, 150, 200, and 250 days. Due to carbonation, chlorartinite was formed on the surface of the examined samples. The Rietveld analysis was performed to calculate the phase composition and evaluate the kinetics of carbonation. The SEM micrographs of the sample surfaces were compared with those of the bulk to prove XRD results. Both MOC phases exhibited fast mineral carbonation and high maximum theoretical values of CO2 uptake capacity. The materials based on MOC cement can thus find use in applications where a higher concentration of CO2 in the environment is expected (e.g., in flooring systems and wall panels), where they can partially mitigate the harmful effects of CO2 on indoor air quality and contribute to the sustainability of the construction industry by means of reducing the carbon footprints of alternative building materials and reducing CO2 concentrations in the environment overall.

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