scholarly journals Preparation and Characterization of Hydroxyapatite by the precipitation method and heat treatment

2020 ◽  
Vol 9 (6) ◽  
pp. e172963549
Author(s):  
Fellype Diorgennes Cordeiro Gomes ◽  
Julia Didier Pedrosa de Amorim ◽  
Girlaine Santos da Silva ◽  
Karina Carvalho de Souza ◽  
Aline Ferreira Pinto ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Tooth Enamel ◽  
Raw Materials ◽  
Calcium Nitrate ◽  
Structural Evolution ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Human Bones

Hydroxyapatite is a synthetic substance in the form of microspheres composed of calcium and phosphate, present in human bones and tooth enamel. The objective of the work was to synthesize hydroxyapatite, from the solution of calcium nitrate and diamonic phosphate by the method of precipitation and heat treatment, obtaining the hydroxyapatite in powder form. To study its structural evolution, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Raman spectroscopy were used. The results show that the hydroxyapatite nanocrystalline can be successfully produced by the precipitation technique from raw materials.

scholarly journals Synthesis and characterization of apatite silicated powders with wet precipitation method

2021 ◽  
Vol 234 ◽  
pp. 00106
Author(s):  
Houda Labjar ◽  
Hassan Chaair
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Analytical Techniques ◽  
Precipitation Method ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wet Precipitation ◽  
Scanning Electron

The synthesis of apatite silicated Ca10(PO4)6-x(SiO4)x(OH)2-x (SiHA) with 0≤x≤2 was investigated using a wet precipitation method followed by heat treatment using calcium carbonate CaCO3 and phosphoric acid H3PO4 and silicon tetraacetate SiC8H20O4 (TEOS) in medium of water ethanol, with three different silicate concentrations. After drying, the samples are ground and then characterized by different analytical techniques like X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning electron Microscopy (SEM) and chemical analysis.

Preparation and Electrochemical Performance of Mn3O4/GR Composites Electrode Material in Supercapacitors

2019 ◽  
Vol 807 ◽  
pp. 50-56
Author(s):  
Yun Long Zhou ◽  
Zhi Biao Hu ◽  
Li Mei Wu ◽  
Jiao Hao Wu
Keyword(s):  
Room Temperature ◽  
Raw Materials ◽  
Precipitation Method ◽  
Electrochemical Performances ◽  
Manganese Sulfate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
A Current ◽  
Discharge Test

Using hydrated manganese sulfate and general type graphene (GR) as raw materials, Mn3O4/GR composite has been successfully prepared by the liquid phase chemical co-precipitation method at room temperature. X-ray diffraction (XRD) was used to investigate the phase structure of Mn3O4powder and Mn3O4/GR composite; The electrochemical performances of the samples were elucidated by cyclic voltammetry and galvanostatic charge-discharge test in 0.5 mol/L Na2SO4electrolyte. The results show that the Mn3O4/GR composite possesses graphene phase and good reversibility; the composite also displays a specific capacitance of 318.8 F/g at a current density of 1 A/g.

In situ characterization of strain-induced crystallization of natural rubber by synchrotron radiation wide-angle X-ray diffraction: construction of a crystal network at low temperatures

Soft Matter ◽  
2019 ◽  
Vol 15 (4) ◽  
pp. 734-743 ◽  
Author(s):  
Pinzhang Chen ◽  
Jingyun Zhao ◽  
Yuanfei Lin ◽  
Jiarui Chang ◽  
Lingpu Meng ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Structural Evolution ◽  
X Ray Diffraction ◽  
In Situ Characterization ◽  
X Ray ◽  
Crystal Network ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

The structural evolution of NR during stretching at −40 °C and in the strain–temperature space.

scholarly journals Cloning, Expression, Purification, and Preliminary Characterization of Single-Crystal X-Ray Diffraction of Glucosyltransferase B of Streptococcus mutans

2019 ◽  
Vol 14 (5) ◽  
pp. 1934578X1984933
Author(s):  
Joshua L. Mieher ◽  
Norbert Schormann ◽  
Manisha Patel ◽  
Hui Wu ◽  
Champion Deivanayagam
Keyword(s):  
Dental Caries ◽  
Oral Cavity ◽  
Single Crystal ◽  
Streptococcus Mutans ◽  
Tooth Enamel ◽  
Tooth Surface ◽  
X Ray Diffraction ◽  
Persistent Disease ◽  
X Ray

Dental caries characterized by acid damage of tooth enamel is a persistent disease that begins with the formation of biofilms on the tooth surface. The secreted glucosyltransferases enable Streptococcus mutans to synthesize extracellular glucan polymers using ingested starch within the oral cavity, which eventually results in the production of acid, a contributing factor to cariogenesis. In this paper, we report the cloning, expression, purification, crystallization, and preliminary X-ray diffraction characterization of glucosyltransferase B.

Characterization of aluminosilicate (mullite) precursors prepared by a mechanochemical process

1998 ◽  
Vol 13 (8) ◽  
pp. 2184-2189 ◽  
Author(s):  
J. Temuujin ◽  
K. Okada ◽  
K. J. D. MacKenzie
Keyword(s):  
Heat Treatment ◽  
Nmr Spectra ◽  
Spinel Phase ◽  
Mas Nmr ◽  
X Ray Diffraction ◽  
Hydrated Alumina ◽  
X Ray ◽  
New Si ◽  
Grinding Time

Aluminosilicate precursors were prepared by mechanochemical treatment of gibbsitesilica gel mixtures. The effect of grinding on their structure and thermal behavior has been examined by 27Al and 29Si MAS NMR, x-ray diffraction (XRD), differential thermal analysis-thermogravimetry (DTA-TG), and Fourier transform infrared (FTIR). After 8 h grinding, the hydrated alumina was completely changed to an amorphous phase which showed a new exothermic DTA peak at about 980 °C due to the formation of γ–Al2O3 or spinel phase. This behavior was related to changes in the Al and Si environments, as deduced from the MAS NMR spectra. With increased grinding time, some 4-coordinated Al appears, together with an Al resonance at about 30 ppm. Simultaneously, a new Si resonance appears at about −90 ppm, indicating a greater degree of homogeneity in the ground samples. Mullite crystallizes at 1200 °C from samples ground for 8–20 h, its XRD intensity increasing with increased milling times, in agreement with the NMR, DTA, and FTIR data. Changes in the Al and Si environments during heat treatment, as reflected by the NMR spectra, are also reported.

Study of Nano-Hydroxyapatite Adsorption in Heavy Metals

2013 ◽  
Vol 777 ◽  
pp. 15-18 ◽  
Author(s):  
Jiu Xu Liu ◽  
Feng Wang ◽  
Jian Xing Shen ◽  
Qi Hui Lai ◽  
Ying Gai
Keyword(s):  
Aqueous Solutions ◽  
Inductively Coupled Plasma ◽  
Raw Materials ◽  
Calcium Nitrate ◽  
Precipitation Method ◽  
Calcium Nitrate Tetrahydrate ◽  
X Ray Diffraction ◽  
Absorption Function ◽  
Inductively Coupled ◽  
Nitrate Tetrahydrate

nanohydroxyapatite (nanoHA) powders were prepared by liquid phase precipitation method, using diammonium hydrogen phosphate and calcium nitrate tetrahydrate as raw materials. It was studied that the prepared nanoHA powders not sintered and sintered at 800°C to adsorption of Cu2+ and Pb2+ in aqueous solutions, respectively. The structure and size of nanoHA powders was investigated by X-ray diffraction (XRD) and the concentrations of Cu2+and Pb2+ in aqueous solutions were tested by inductively coupled plasma emission spectrometer. The results revealed that the nanoHA powders have obvious absorption function for Cu2+ and Pb2+ in aqueous solutions. In addition, the absorption ratio was affected by the size of nanoHA.

Neodymium Incorporation in Zirconolite-Based Glass-Ceramics

2000 ◽  
Vol 663 ◽  
Author(s):  
P. Loiseau ◽  
D. Caurant ◽  
N. Baffier ◽  
C. Fillet
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Fission Products ◽  
Treatment Temperature ◽  
Spent Fuel ◽  
X Ray Diffraction ◽  
Parent Glass ◽  
X Ray ◽  
Spin Resonance

ABSTRACTThe investigations on enhanced reprocessing of nuclear spent fuel, and notably on separating the long-lived minor actinides, such as Am and Cm, from the other fission products have led to the development of highly durable specific matrices such as glass-ceramics for their immobilization. This study deals with the characterization of zirconolite (CaZrTi2O7) based glass-ceramics synthesized by devitrification of an aluminosilicate parent glass. Trivalent actinide ions were simulated by neodymium, which is a paramagnetic local probe. Glass-ceramics with Nd2O3 contents ranging from 0 to 10 weight % were prepared by heat treatment of a parent glass at two different growth temperatures: 1050° and 1200°C. X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and electron spin resonance (ESR) measurements clearly indicate that Nd3+ ions are partly incorporated in zirconolite crystals formed in the bulk of the glass-ceramic samples. The amount of neodymium in the crystalline phase was estimated using ESR results and was found to decrease with increasing either heat treatment temperature or total Nd2O3 content.

Synthesis and Characterization of Zinc Doped Hydroxyapatite for Bone Substitute Applications

2014 ◽  
Vol 660 ◽  
pp. 942-946
Author(s):  
Mohamad Firdaus Abdul Wahid ◽  
C.M. Mardziah ◽  
Koay Mei Hyie ◽  
N.R. Nik Roselina
Keyword(s):  
Crystal Size ◽  
Diffraction Method ◽  
Lattice Parameters ◽  
Phase Changes ◽  
Precipitation Method ◽  
Zinc Ions ◽  
Crystal Shape ◽  
X Ray Diffraction ◽  
X Ray

Hydroxyapatite was prepared by using precipitation method. The substitution of zinc ions in hydroxyapatite structure was studied by several characterization techniques. Several concentration of zinc ions were substituted into hydroxyapatite. Characterization technique such as X-ray diffraction method was used to study the phase changes and the lattice parameters with the addition of zinc. Field emission scanning electron microscopy was used to examine the influence of zinc on the crystal size and the morphology of the as-synthesized powders. Based on X-ray diffraction result, the addition of zinc affects the lattice parameters and phase. The result showed that zinc ions were substituted in the structure. As zinc substitution increased, the lattice parameters a and c decreased. The crystal shape of hydroxyapatite without zinc ions was regular shapes while hydroxyapatite with zinc ions was irregular and also tends to agglomerates with single particle was calculated about 28 - 34 nm .

Synthesis and Characterization of New Polyurethane Adhesives

2006 ◽  
Vol 514-516 ◽  
pp. 843-847 ◽  
Author(s):  
Cristina Borges Correia ◽  
João C. Bordado
Keyword(s):  
Raw Materials ◽  
Impact Resistance ◽  
Inert Atmosphere ◽  
Stray Field ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Polyurethane Adhesives ◽  
Dimer Acids

Polyurethane adhesives provide excellent flexibility, impact resistance and durability. Polyurethanes are formed through the reaction of an isocyanate component with polyether or polyester polyols or other active hydrogen compounds. This paper refers to polyurethane adhesives made from polyester polyols with long aliphatic chains (up to 36 carbon atoms) and MDI (diphenylmethane-4,4’-diisocyanate). The polyester polyols have been made from dimer acids obtained from renewable sources and short chain diols. The polyols that were used presented different degrees of unsaturation. The influence of the different raw materials in the adhesives performance is studied. The polyurethanes were produced by reaction between quasi-stoichiometric quantities of polyol and MDI, at several temperatures. The reaction was carried under inert atmosphere and at temperatures below 100°C. Performance of the adhesives was tested by carrying adhesion, hardness and water absorption tests. Characterization of both the polyester polyols and polyurethane adhesives was carried by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Magnetic Nuclear Resonance (NMR), X-Ray Diffraction (WAXD), Scanning RMN Imaging of 1H of Stray- Field b (MRI) and Brookfield viscometry.

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