scholarly journals Synthesis and Mechanism of Tetracalcium Phosphate from Nanocrystalline Precursor

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Jianguo Liao ◽  
Xingze Duan ◽  
Yanqun Li ◽  
Caifeng Zheng ◽  
Zhengpeng Yang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Calcination Temperature ◽  
X Ray Diffraction ◽  
Tetracalcium Phosphate ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
Ir And Raman ◽  
Cooling Methods

Tetracalcium phosphate (TTCP, Ca4(PO4)2O) was prepared by the calcination of coprecipitated mixture of nanoscale hydroxyapatite (HA, Ca10(PO4)6(OH)2) and calcium carbonate crystal (CaCO3), followed by cooling in the air or furnace. The effect of calcination temperature on crystal structure and phase composition of the coprecipitation mixture was characterized by transmission electron microscope (TEM), thermal analysis-thermogravimetry (DTA-TG), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), and Raman spectroscopy (RS). The obtained results indicated that the synthesized mixture consisted of nanoscale HA and CaCO3with uniform distribution throughout the composite. TTCP was observed in the air quenching samples when the calcination temperature was above 1185°C. With the increase of the calcination temperature, the amount of the intermediate products in the air quenching samples decreased and cannot be detected when calcination temperature reached 1450°C. Unexpectedly, the mixture of HA and calcium oxide was observed in the furnace cooling samples. Clearly, the calcination temperature and cooling methods are critical for the synthesis of high-purity TTCP. The results indicate that the nanosize of precursors can decrease the calcination temperature, and TTCP can be calcinated by low temperature.

scholarly journals The Effect of Calcination Temperature on the Structure and Performance of Nanocrystalline Mayenite Powders

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3476 ◽  
Author(s):  
Katarzyna Berent ◽  
Sebastian Komarek ◽  
Radosław Lach ◽  
Waldemar Pyda
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Calcination Temperature ◽  
Phase Formation ◽  
Crystalline Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Appreciable Increase ◽  
And Performance

The effect of calcination temperature on the structural properties and phase formation of synthesized CaO-Al2O3 nanopowder was investigated and discussed. The calcination products were identified by differential thermal analysis (DTA) and the crystalline phase formation was analyzed by X-ray diffraction (XRD). The obtained results showed that the crystallization started at 460 °C. Finally, the microstructures of the nanoparticles were observed by scanning (SEM) and transmission electron (TEM) microscopes. The investigation showed that an increase in the calcination temperature led to the appreciable increase in the crystallite size and the crystallinity of the final product. The obtained data confirmed that the prepared materials were mayenite with different surface area in the range of 71.18 m2/g to 10.34 m2/g after annealing in the temperature range of 470 °C to 960 °C.

Synthesis of magnesium hydroxide nanoneedles and short nanorods on polymer dispersant template

2007 ◽  
Vol 22 (9) ◽  
pp. 2544-2549 ◽  
Author(s):  
Hong Yan ◽  
Jianming Wu ◽  
Xuehu Zhang ◽  
Yan Zhang ◽  
Liqiao Wei ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Thermal Analysis ◽  
Magnesium Hydroxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Polymer Dispersant ◽  
Short Nanorods ◽  
Reverse Precipitation

Magnesium hydroxide nanoneedles and nanorods were synthesized by reverse precipitation in the presence of polyethylene glycol (MW 1000) at ambient temperature. The obtained magnesium hydroxide crystals were characterized in terms of morphology, particle size, crystal structure, and thermal stability by high-resolution transmission electron microscopy, x-ray diffraction, infrared spectroscopy, and thermogravimetric and differential thermal analysis. The experimental results show that the growth of magnesium hydroxide crystals and the dispersivity of the nanostructures were greatly influenced by polymer dispersant. The mechanism of the formation of magnesium hydroxide nanorods and nanoneedles was also proposed.

Large Reversible Capacity of Graphene Electrodes Used in Lithium-Ion Batteries

2013 ◽  
Vol 320 ◽  
pp. 114-118
Author(s):  
Li Zhong Bai ◽  
Dong Lin Zhao ◽  
Ji Ming Zhang ◽  
Feng Li
Keyword(s):  
Electron Microscope ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
X Ray Diffraction ◽  
Natural Graphite ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir ◽  
Ir And Raman ◽  
A Current

High quality graphene sheets (GSs) were prepared from natural graphite by oxidation, rapid thermal expansion and ultrasonic treatment. The morphology and structure of GSs were systematically investigated by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier tansform infrared spectroscopy (FT-IR) and Raman spectroscopy. It was found that the GSs electrode used in lithium-ion battery (LIB) exhibited a relatively high reversible capacity of 902 mA h/g at a current density of 50 mA/g. After 50 cycles, the reversible capacity was still kept at 734 mA h/g.

Synthesis, crystal structure, luminescence, and photocatalytic properties of a 2D Cu(II) metal-organic frameworks based on 3,5-di(1H-benzimidazol-1-yl)pyridine and 4,4′-oxybis(benzoate) ligands

2020 ◽  
Vol 75 (8) ◽  
pp. 727-732
Author(s):  
Chen Zhang ◽  
Jian-Qing Tao
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Uv Light ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Light Irradiation ◽  
Photocatalytic Activities ◽  
Metal Organic

AbstractA new Cu(II) metal-organic framework, [Cu(L)(OBA)·H2O]n (1) [H2OBA = 4,4′-oxybis(benzoic acid), L = 3,5-di(1H-benzimidazol-1-yl)pyridine] was hydrothermally synthesized and characterized through IR spectroscopy, elemental and thermal analysis and single-crystal X-ray diffraction. Complex 1 is a four-connected uni-nodal 2D net with a (44·62) topology which shows an emission centered at λ ∼393 nm upon excitation at λ = 245 nm. Moreover, complex 1 possesses high photocatalytic activities for the decomposition of Rhodamine B (RhB) under UV light irradiation.

scholarly journals Hydrothermal Synthesis, Characterization and Exploration of Photocatalytic Activities of Polyoxometalate: Ni-CoWO4 Nanoparticles

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 456
Author(s):  
Fahad A. Alharthi ◽  
Hamdah S. Alanazi ◽  
Amjad Abdullah Alsyahi ◽  
Naushad Ahmad
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Photocatalytic Activities ◽  
Ft Ir ◽  
Photocatalytic Reactions ◽  
Cobalt Tungstate

This study demonstrated the hydrothermal synthesis of bimetallic nickel-cobalt tungstate nanostructures, Ni-CoWO4 (NCW-NPs), and their phase structure, morphology, porosity, and optical properties were examined using X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscopy- energy dispersive X-ray spectroscopy (SEM-EDS), high resolution Transmission electron microscopy (HR-TEM), Brunauer-Emmett-Teller (BET) and Raman instruments. It was found that as-calcined NCW-NPs have a monoclinic phase with crystal size ~50–60 nm and is mesoporous. It possessed smooth, spherical, and cubic shape microstructures with defined fringe distance (~0.342 nm). The photocatalytic degradation of methylene blue (MB) and rose bengal (RB) dye in the presence of NCW-NPs was evaluated, and about 49.85% of MB in 150 min and 92.28% of RB in 90 min degraded under visible light. In addition, based on the scavenger’s study, the mechanism for photocatalytic reactions is proposed.

Darstellung, 11B-, 13C-, 29Si-NMR- und Schwingungsspektren von Trimethylsilylmethyl-hexahydro-closo-hexaborat, [B6H6(CH2Si(CH3)3)]- sowie Kristallstruktur von [P(C6H5)4][B6H6(CH2Si(CH3)3)] / Preparation, 11B, 13C, 29Si NMR and Vibrational Spectra of Trimethylsilylmethyl-hexahydro-clo-hexaborate, [B6H6(CH2Si(CH 3)3)]-and the Crystal Structure of [P(C6H5)4] [B6H6(CH2Si(CH3)3)]

1995 ◽  
Vol 50 (7) ◽  
pp. 1025-1029 ◽  
Author(s):  
J. Baurmeister ◽  
A. Franken ◽  
W. Preetz
Keyword(s):  
Crystal Structure ◽  
Monoclinic Space Group ◽  
29Si Nmr ◽  
X Ray Diffraction ◽  
Nmr Spectrum ◽  
X Ray ◽  
Quadrupole Coupling ◽  
Stretching Vibration ◽  
Ir And Raman ◽  
C Nmr

By reaction of [N(C4H9 )4]2 [B6H6] with iodomethyl-trimethylsilane in acetonitrile a solution with trimethylsilylm ethyl-closo-hexaborate(1-)anions, [B6H6 (CH2Si(CH3)3)]-, is formed. The crystal structure of [P(C6H5 )4][B6H6(CH2Si(CH3)3)] has been determined by single crystal X-ray diffraction analysis; monoclinic, space group P21/n with a = 16.140(2), b = 11.646(8), c = 16.731(3) Å, β 109.664(11)°. The 11B NMR spectrum reveals features of a mono hetero substituted octahedral B6 cage. The 13C NMR spectrum exhibits a quartet at +0.18 ppm with 1J(C,H) = 118 Hz for the three methyl groups and a weak multiplet at -0.65 ppm for the methylene bridge due to quadrupole coupling with the boron atoms. In the 29Si NMR spectrum a decet at +2.25 ppm with 2J(C,H ) = 6.9 Hz is observed. The B -C stretching vibration is observed at 1155 cm-1 in the IR and Raman spectrum.

On tungstates of divalent cations (III) – Pb5O2[WO6]

2020 ◽  
Vol 235 (8-9) ◽  
pp. 311-317
Author(s):  
Stephan G. Jantz ◽  
Florian Pielnhofer ◽  
Henning A. Höppe
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Quantum Chemical ◽  
Density Functional ◽  
Divalent Cations ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
First Results ◽  
Electrostatic Calculations

Abstract${\text{Pb}}_{5}{\text{O}}_{2}\left[{\text{WO}}_{6}\right]$ was discovered as a frequently observed side phase during our investigation on lead tungstates. Its crystal structure was solved by single-crystal X-ray diffraction ($P{2}_{1}/n$, $a=7.4379\left(2\right)$ Å, $b=12.1115\left(4\right)$ Å, $c=10.6171\left(3\right)$ Å, $\beta =90.6847\left(8\right)$°, $Z=4$, ${R}_{\text{int}}=0.038$, ${R}_{1}=0.020$, $\omega {R}_{2}=0.029$, 4188 data, 128 param.) and is isotypic with ${\text{Pb}}_{5}{\text{O}}_{2}\left[{\text{Te}}_{6}\right]$. ${\text{Pb}}_{5}{\text{O}}_{2}\left[{\text{WO}}_{6}\right]$ comprises a layered structure built up by non-condensed [WO6]${}^{6-}$ octahedra and ${\left[{\text{O}}_{4}{\text{Pb}}_{10}\right]}^{12+}$ oligomers. The compound was characterised by spectroscopic measurements (Infrared (IR), Raman and Ultraviolet–visible (UV/Vis) spectra) as well as quantum chemical and electrostatic calculations (density functional theory (DFT), MAPLE) yielding a band gap of 2.9 eV fitting well with the optical one of 2.8 eV. An estimation of the refractive index based on the Gladstone-Dale relationship yielded $n\approx 2.31$. Furthermore first results of the thermal analysis are presented.

Luminescent Properties of Zn2SiO4:Eu3+,Dy3+ Phosphors via Sol-Gel Process

2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi
Keyword(s):  
Thermal Analysis ◽  
Ir Spectra ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Ft Ir

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.

One Step Synthesis and Characterization of Zirconia-Graphene Composites

2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
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.

scholarly journals Novel solid forms of the analgesic drug ethenzamide

2014 ◽  
Vol 70 (a1) ◽  
pp. C995-C995
Author(s):  
Duane Choquesillo-Lazarte ◽  
Cristóbal Verdugo-Escamilla ◽  
Juan Manuel García-Ruiz
Keyword(s):  
Polycrystalline Material ◽  
X Ray Diffraction ◽  
Analgesic Drug ◽  
X Ray ◽  
Solution Methods ◽  
Additional Stability ◽  
Ft Ir ◽  
Model Drug ◽  
Solid Form ◽  
Ir And Raman

The interest in multicomponent solid forms has increased in the last years within the pharmaceutical industry and also the solid-state community due to the possibility of obtaining materials with new properties [1]. Crystallization strategies, supported by solvent- and solid-based techniques, have also received attention in the search and development of methodologies for the screening of multicomponent crystals. In this work, ethenzamide, an anti-inflammatory and analgesic drug, was selected as a model drug to develop cocrystals on the basis of the synthon types using a series of phenolic coformers. Ethenzamide cocrystals and cocrystal solvates have been reported recently [2,3]. Liquid Assisted Grinding (LAG) and solution methods were used as synthetic tools. Attempts to produce cocrystals by LAG and Reaction Crystallization led to the formation of polycrystalline material. The solids obtained were then characterized by powder X-ray diffraction (PXRD), FT-IR and Raman spectroscopy. Recrystallization by slow solvent evaporation was carried out when the above-referred techniques strongly suggest the formation of a new solid form. The structure of five new multicomponent solids has been determined by single crystal X-ray diffraction. Additional stability studies have been performed at controlled relative humidity conditions and followed by PXRD.

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