MECHANOCHEMICAL SYNTHESIS OF NANOCRYSTALLINE FLUORINATED HYDROXYAPATITE

2005 ◽  
Vol 04 (04) ◽  
pp. 643-649 ◽  
Author(s):  
N. RAMESHBABU ◽  
T. S. SAMPATH KUMAR ◽  
R. MURUGAN ◽  
K. PRASAD RAO
Keyword(s):  
Laser Raman Spectroscopy ◽  
Mechanochemical Processing ◽  
Fluorine Substitution ◽  
X Ray ◽  
Laser Raman ◽  
Fine Grain ◽  
Transmission Electron ◽  
Ft Ir ◽  
Synthetic Hydroxyapatite ◽  
Nano Size

Synthetic hydroxyapatite ( Ca 10( PO 4)6( OH )2, HA ) is an important material used for orthopaedic and dental implant applications. The biological hydroxyapatite in the human bone and tooth is of nano size and differs in composition from the stiochiometric HA by the presence of other ions such as carbonate, magnesium and fluoride, etc. Osseointegration is enhanced by using nanocrystalline HA . This stimulates the interest in synthesizing nanocrystalline HA by different routes and among the methods, mechanochemical seems to form fine grain size and uniform characteristic nanocrystalline materials. Fluorinated hydroxyapatite ( FHA , Ca 10( PO 4)6( OH )2-x F x) possesses higher corrosion resistance in biofluids than pure HA and reduces the risk of dental caries. The present work deals with the synthesis of nanocrystalline FHAs by mechanochemical processing. The nanomaterials were characterized using X-ray powder diffraction (XRD) and transmission electron microscopy (TEM) methods. Nano FHA of about 27-46 nm size was observed. The functional groups present in the FHA powders were ascertained by Fourier transform infrared spectroscopy (FT-IR) and Laser Raman spectroscopy. A gradual decrease in intensity of the OH - band at 655 and 3572 cm-1 has been observed with increasing fluorine substitution. The TEM micrograph shows that the powder is highly agglomerated and particle size is below 50 nm.

X-ray powder diffraction data for a new compound (NH4)H2Co2O(OH)(MoO4)1.6(WO4)0.4•H2O type ϕy

2018 ◽  
Vol 33 (4) ◽  
pp. 315-318 ◽  
Author(s):  
Adriana Echavarría ◽  
Sandra L. Amaya
Keyword(s):  
Raman Spectroscopy ◽  
Lamellar Structure ◽  
Laser Raman Spectroscopy ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Hexagonal Symmetry ◽  
X Ray ◽  
Laser Raman ◽  
Ir Laser ◽  
Ft Ir

A new trimetallic compound with formula (NH4)H2Co2O(OH)(MoO4)1.6(WO4)0.4•H2O and lamellar structure was prepared by hydrothermal synthesis. The solid was characterized using X-ray diffraction (XRD), thermogravimetric (TGA) and differential thermal (DTA) analyses, Fourier-transform infrared spectroscopy (FT–IR), laser Raman spectroscopy (LRS), and atomic absorption spectroscopy (AA). Crystallographic studies showed that the solid crystallizes with hexagonal symmetry in space group R-3 m with a = 6.0807 and c = 21.7591 Å.

Preparation of Graphene by Green Reduction Method and Characterization

2013 ◽  
Vol 807-809 ◽  
pp. 515-520 ◽  
Author(s):  
Dong Zhi Chen ◽  
Xue Mei Lin
Keyword(s):  
Electrical Conductivity ◽  
Graphene Oxide ◽  
Graphite Oxide ◽  
Laser Raman Spectroscopy ◽  
X Ray Diffraction ◽  
Ultrasonic Dispersion ◽  
Environment Friendly ◽  
X Ray ◽  
Laser Raman ◽  
Transmission Electron

Graphite oxide was prepared by Hummers method and got graphene oxide by ultrasonic dispersion in water, and using a cheap and environment-friendly fructose as reductant, graphene oxide could be reduced into graphene under mild condition. Meanwhile, the structure and morphology of obtained product was characterized and analyzed by testing methods such as Fourier transform Infrared spectroscopy, X-ray diffraction, Laser Raman spectroscopy, Transmission electron microscope and so on. In addition, the electrical conductivity of obtained graphene was determinated.The experimental results show that graphite oxide can be reduced by fructose under mild conditions and can get graphene with good structure and dispersibility. And the electrical conductivity of graphene prepared by the reduction of graphite oxide with fructose is 35.7 Scm-1, which has great improvement on conducting performance compared with graphite oxide. Moreover, It is non-toxic, non-polluting and friendly to the environment in preparation process of graphene, which lays the groundwork for mass production of graphene materials.

Absorbing Manganese Oxide on Multi-Walled Carbon Nanotubes

2007 ◽  
Vol 121-123 ◽  
pp. 85-88
Author(s):  
Xian Ping Huang ◽  
Chun Xu Pan
Keyword(s):  
Carbon Nanotubes ◽  
Laser Raman Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Laser Raman ◽  
Transmission Electron ◽  
Mno2 Nanoparticles ◽  
Multi Walled Carbon Nanotubes ◽  
Cnts Surface ◽  
Walled Carbon Nanotubes

A layer of Manganese dioxides (γ-MnO2) was absorbed upon carbon nanotubes (CNTs) surface by using a chemical deposit process. The morphologies of the MnO2/CNTs composite were characterized using transmission electron microscopy (TEM), energydispersive X-ray spectrometry (EDS), X-ray diffraction (XRD) and laser Raman spectroscopy (RS). It is found that absorbed layer belongs to the γ-MnO2 nanoparticles in size about 10 nm, and coated homogeneously around the CNTs. It is expected that this MnO2/CNTs composite will be widely applied to make supercapacitors.

Aspects of microanalysis in a transmission electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 510-511
Author(s):  
R. Sinclair ◽  
B.E. Jacobson
Keyword(s):  
Grain Size ◽  
Electron Beam ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Transmission Electron Microscope ◽  
Vapor Deposition ◽  
Critical Currents ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).

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.

Effect of Calcinations on Characterizations of Fabricated Nano Manganese Ferrite

2013 ◽  
Vol 634-638 ◽  
pp. 2150-2154 ◽  
Author(s):  
Rita Sundari ◽  
Tang Ing Hua ◽  
M. Rusli Yosfiah
Keyword(s):  
Sol Gel ◽  
Volatile Components ◽  
Manganese Ferrite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Reflectance Analysis ◽  
Transmission Electron Microscope Analysis ◽  
Electron Microscope Analysis ◽  
Nano Size

A citric acid anionic surfactant has been applied for nano manganese ferrite (MnFeO3) fabrication using sol gel method. The calcinations have been varied for 300, 600 and 800oC. The UVDR (UV-Vis Diffused Reflectance) analysis shows a high absorptive band gap after 400 nm for the 600oC calcinated MnFeO3. The DTA (Differential Thermal Analysis) profiles exhibit remarkably trapped volatile matters (H2O, CO2, and NO2) in the fabricated MnFeO3 under sol gel heat treatment at 100oC and the peaks disappeared as the calcination increased to 600oC. As the temperature elevated from 100 to 300oC, the absorption peaks of volatile components are disappeared as demonstrated clearly by the FTIR (Fourier Transform Infrared) spectra of the fabricated material, which 3393 cm-1 corresponded to OH group, 1624 cm-1 to CO group, and 1384 cm-1 to NO group. The XRD (X-Ray Diffraction) spectra show clearly the alteration process from amorphous to crystalline structure as the calcinations increased from 300 to 600oC. In addition, the TEM (Transmission Electron Microscope) analysis exhibits parts of the fabricated MnFeO3 found in cubic nano size of 15-40 nm under interested calcinations and the result is in agreement with that obtained by XRD investigation.

Detonation Synthesis of Nano-Size Materials

1995 ◽  
Vol 418 ◽  
Author(s):  
J. Forbes ◽  
J. Davis ◽  
C. Wong
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nucleation And Growth ◽  
Detonation Synthesis ◽  
X Ray Diffraction ◽  
Crystalline Materials ◽  
X Ray ◽  
Transmission Electron ◽  
Nano Size

AbstractThe detonation of explosives typically creates 100's of kbar pressures and 1000's K temperatures. These pressures and temperatures last for only a fraction of a microsecond as the products expand. Nucleation and growth of crystalline materials can occur under these conditions. Recovery of these materials is difficult but can occur in some circumstances. This paper describes the detonation synthesis facility, recovery of nano-size diamond, and plans to synthesize other nano-size materials by modifying the chemical composition of explosive compounds. The characterization of nano-size diamonds by transmission electron microscopy and electron diffraction, X-ray diffraction and Raman spectroscopy will also be reported.

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.

Effect of Synthesis Temperature on Particles Size and Morphology of Zirconium Oxide Nanoparticle

2017 ◽  
Vol 50 ◽  
pp. 18-31 ◽  
Author(s):  
Rudzani Sigwadi ◽  
Simon Dhlamini ◽  
Touhami Mokrani ◽  
Patrick Nonjola
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Zirconium Oxide ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Crystallite Sizes ◽  
Ft Ir

The paper presents the synthesis and investigation of zirconium oxide (ZrO2) nanoparticles that were synthesised by precipitation method with the effects of the temperatures of reaction on the particles size, morphology, crystallite sizes and stability at high temperature. The reaction temperature effect on the particle size, morphology, crystallite sizes and stabilized a higher temperature (tetragonal and cubic) phases was studied. Thermal decomposition, band structure and functional groups were analyzed by Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Thermo-gravimetric analysis (TGA) and Fourier transform infrared (FT-IR). The crystal structure was determined using X-ray diffraction. The morphology and the particle size were studied using (SEM) and (TEM). The shaped particles were confirmed through the SEM analysis. The transmission electron microscopic analysis confirmed the formation of the nanoparticles with the particle size. The FT-IR spectra showed the strong presence of ZrO2 nanoparticles.

scholarly journals Dual Light- and pH-Responsive Composite of Polyazo-Derivative Grafted Cellulose Nanocrystals

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1725 ◽  
Author(s):  
Xiaohong Liu ◽  
Ming Li ◽  
Xuemei Zheng ◽  
Elias Retulainen ◽  
Shiyu Fu
Keyword(s):  
Cellulose Nanocrystals ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
X Ray Diffraction ◽  
Responsive Materials ◽  
X Ray ◽  
Ph Response ◽  
Transmission Electron ◽  
Ft Ir ◽  
Hexyl Methacrylate

As a type of functional group, azo-derivatives are commonly used to synthesize responsive materials. Cellulose nanocrystals (CNCs), prepared by acid hydrolysis of cotton, were dewatered and reacted with 2-bromoisobuturyl bromide to form a macro-initiator, which grafted 6-[4-(4-methoxyphenyl-azo) phenoxy] hexyl methacrylate (MMAZO) via atom transfer radical polymerization. The successful grafting was supported by Fourier transform infrared spectroscopy (FT-IR) and Solid magnetic resonance carbon spectrum (MAS 13C-NMR). The morphology and surface composition of the poly{6-[4-(4-methoxyphenylazo) phenoxy] hexyl methacrylate} (PMMAZO)-grafted CNCs were confirmed with Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The grafting rate on the macro-initiator of CNCs was over 870%, and the polydispersities of branched polymers were narrow. The crystal structure of CNCs did not change after grafting, as determined by X-ray diffraction (XRD). The polymer PMMAZO improved the thermal stability of cellulose nanocrystals, as shown by thermogravimetry analysis (TGA). Then the PMMAZO-grafted CNCs were mixed with polyurethane and casted to form a composite film. The film showed a significant light and pH response, which may be suitable for visual acid-alkali measurement and reversible optical storage.

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