Synthesis and Characterization of Fe3O4 Nanoparticles Stabilized by Polyvinylpyrrolidone/Polyethylene Glycol with Variable Mass Ratios

2016 ◽  
Vol 869 ◽  
pp. 880-883
Author(s):  
Fernanda A. Sampaio da Silva ◽  
Marcos Flavio de Campos ◽  
Edwin E.G. Rojas
Keyword(s):  
Polyethylene Glycol ◽  
Variable Mass ◽  
Rietveld Analysis ◽  
Polymer Mixture ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
Cancer Treatments ◽  
Varying Mass ◽  
Good Agreement

Magnetic nanoparticles are devices able to optimize cancer treatments. In particular, magnetite nanoparticles are very effective in producing heat to cause lysis of tumor cells. However, in order that nanoparticles are internalized without causing damage to body they must be coated by biocompatible material. In this work, Fe3O4 nanoparticles were coated by a polymer blend: polyethylene glycol / polyvinylpyrrolidone. Some variations in mass ratio of polymer mixture were made. The effect of varying mass ratio in polymers was investigated. Samples were characterized by X-ray diffraction and Rietveld analysis. Moreover, hysteresis curves were analyzed. The results indicate good agreement between mass proportions used and physical and magnetic properties of nanocomposite.

scholarly journals Rietveld Method Applied for Triacylglycerol Polymorphism Analysis

2014 ◽  
Vol 70 (a1) ◽  
pp. C1764-C1764
Author(s):  
Guilherme Calligaris ◽  
Ana Paula Ribeiro ◽  
Adenilson dos Santos ◽  
Lisandro Cardoso
Keyword(s):  
Rietveld Method ◽  
Rietveld Analysis ◽  
Polymorphic Form ◽  
Polymorphism Analysis ◽  
X Ray Diffraction ◽  
Full Characterization ◽  
Β Phase ◽  
Lack Of Information ◽  
Refinement Method

The characterization of the fat components becomes very useful in the formulation of shortening, margarines and fatty products due to their unique properties of plasticity, texture, solubility and aeration. The qualitative analysis obtained by X-ray diffraction (XRD) can be further improved in order to fulfill the lack of information on the triacylglycerol (TAG) in the hardfat systems aiming a complete polymorph characterization. In this work, as an attempt to quantify the distinct β and β' TAG polymorphs, XRD was combined with Rietveld refinement method and applied to two types of samples: mixtures (M) and blended hardfats (B) samples involving fully hydrogenated of soybean (FHSO) and palm (FHPO) oils. M-samples were prepared with linear concentrations of FHSO (β) and FHPO (β') and their Rietveld analysis have provided the expected content trend through the involved polymorphic phases with a very good agreement (~5%). This result validates the Rietveld method applicability on this kind of materials. The Rietveld method applied for B-samples has shown that β' polymorphic form prevails over the β-form, even for samples originally prepared with FHSO (β)/FHPO (β') = 60/40 ratio (see figure). This result indicates the influence of the seeding process (earlier crystallization of β' phase). This first quantitative approach for blended samples represents a very useful contribution towards the full characterization of fats.

CONTROLLED SYNTHESIS AND CHARACTERIZATION OF TiO2 NANOPARTICLES VIA A SOL–GEL METHOD

2004 ◽  
Vol 03 (06) ◽  
pp. 749-755 ◽  
Author(s):  
YING LI ◽  
SUO HON LIM ◽  
TIM WHITE
Keyword(s):  
Sol Gel ◽  
Critical Role ◽  
Rietveld Analysis ◽  
Nanocrystalline Powders ◽  
X Ray Diffraction ◽  
Gelation Temperature ◽  
Gel Method ◽  
Sol Gel Method ◽  
Transmission Electron

The properties influencing the photocatalytic activity of TiO 2 particles have been suggested to include the surface area, crystallinity, crystallite size and crystal structure. Therefore, manipulation of the microstructure of titania, especially of nanocrystalline powders, is very important in the preparative process. In this study, nanocrystalline TiO 2 powders with controlled particle size and phase composition were synthesized at low temperature (<80°C) by a modified sol–gel method. The effects of gelation temperature were systematically investigated. It was found that this parameter played a critical role in determining the crystallinity of single phase anatase. With increasing gelation temperature, the crystallinity of anatase improved initially and then decreased if the temperature was raised to 80°C. These nanomaterials were characterized comprehensively by powder X-ray diffraction (including Rietveld analysis), high-resolution transmission electron microscopy, DSC/TGA thermal analysis and UV–Vis spectrometry.

The Synthesis of Ce-Filled CoSb3 and Characterization of its Magnetic and Structural Properties

2003 ◽  
Vol 793 ◽  
Author(s):  
Arwyn L. E. Smalley ◽  
Brandon Howe ◽  
David C. Johnson
Keyword(s):  
Low Temperatures ◽  
Magnetic Measurements ◽  
Rietveld Analysis ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
X Ray ◽  
Ferromagnetic Component ◽  
Phase Pure ◽  
Powder Samples

ABSTRACTA series of cerium-containing CoSb3 samples were synthesized, with cerium quantities varying from 0 to 2 stoichiometric equivalents. These samples were annealed at low temperatures to crystallize the kinetically stable phases CexCo4Sb12 (x = 0–0.5). X-ray diffraction showed that these samples were phase pure, and Rietveld analysis on x-ray diffraction data from powder samples indicated that these samples were 25–88% crystalline. Electrical measurements showed that these samples are n-type, which was previously unknown in CexCo4Sb12. Magnetic measurements showed that the samples were paramagnetic due to the cerium being incorporated into the diamagnetic CoSb3 compound. In addition, they contained a ferromagnetic component that was attributed to the amorphous, cerium-containing phase.

scholarly journals Preparation of Zirconium Oxide Powder Using Zirconium Carboxylate Precursors

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Mohammed H. Al-Hazmi ◽  
YongMan Choi ◽  
Allen W. Apblett
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Dissociative Adsorption ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
Experimental Findings ◽  
Periodic Dft Calculations ◽  
Good Agreement

Zirconia was prepared at low temperatures (<450°C) using single several source precursors based on zirconium carboxylates where the R groups were systematically varied. The combination of density functional theory (DFT) calculations and extensive characterization of the precursors (i.e., X-ray diffraction, thermal gravimetric analysis, infrared spectroscopy, and scanning electron microscopy) indicated that the carboxylic acid complexes may link the zirconium metal with a cis bidentate configuration. Periodic DFT calculations were performed to examine the interaction between monoclinic ZrO2 and propanoic acid. Dissociative adsorption takes place through the cis bidentate structure with an adsorption energy of −1.43 eV. Calculated vibrational frequencies using the optimized structure are in good agreement with experimental findings.

Characterization of the Residual Stresses and Strength of Ceramic-Metal Braze Joints

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Matteo Galli ◽  
John Botsis ◽  
Jolanta Janczak-Rusch ◽  
Gerd Maier ◽  
Udo Welzel
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Finite Element Models ◽  
Plastic Response ◽  
X Ray Diffraction ◽  
Elastoplastic Properties ◽  
Bend Tests ◽  
Point Bend ◽  
Good Agreement

Residual stress relief in ceramic-metal joints produced by active brazing depends primarily on the plastic response of the filler metal. A procedure for the production and mechanical characterization of bulk active filler alloy specimens is developed. In parallel ceramic-metal joints are produced and tested. Residual stresses are measured by X-ray diffraction while the joint strength is assessed by four-point bend tests. The obtained elastoplastic properties of the filler are introduced into finite element models to predict the residual stresses in the joints and their behavior in bending. The results of the simulations show good agreement both with the residual stress measurements and with the results of four-point bend tests.

STRUCTURAL AND OPTICAL CHARACTERIZATION OF NANOCRYSTALLINE CuAlS2 CHALCOPYRITE SYNTHESIZED BY POLYOL METHOD IN AUTOCLAVE

2012 ◽  
Vol 26 (31) ◽  
pp. 1250179 ◽  
Author(s):  
Y. VAHIDSHAD ◽  
A. IRAJIZAD ◽  
R. GHASEMZADEH ◽  
S. M. MIRKAZEMI ◽  
A. MASOUD
Keyword(s):  
Electron Microscope ◽  
Polyethylene Glycol ◽  
Scanning Electron Microscope ◽  
Optical Characterization ◽  
Polyol Method ◽  
Capping Agent ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Chalcopyrite CuAlS 2 nanoparticles were synthesized with polyol method. The solvothermal with autoclave nanoparticles synthesized are investigated. The amount and temperature of reducer, the solvent of salts could be important parameters that were studied. The nanoparticles were synthesized with CuCl , AlCl 3 and thiourea ( SC ( NH 2)2) as precursors, diethylene glycol (( CH 2 CH 2 OH )2 O ) and polyethylene glycol 600 ( HO ( C 2 H 4 O )n H ) as solvent and capping agent respectively, and ammonia ( NH 4 OH ) as reducing agent. The parameters of synthesis were studied by X-Ray diffraction (XRD) for analysis of structure, scanning electron microscope (SEM) for morphology and by ultraviolet–visible (UV–VIS) spectrophotometer for analysis of light structure. The possible formation mechanism is also discussed.

Growth and structural characterization of Cu2ZnSnSe4 compound for solar cells

2014 ◽  
Vol 92 (7/8) ◽  
pp. 902-904 ◽  
Author(s):  
N. Seña ◽  
F. Mesa ◽  
A. Dussan ◽  
G. Gordillo
Keyword(s):  
Thin Films ◽  
Structural Characterization ◽  
Deposition Temperature ◽  
Mass Ratio ◽  
Electrical Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Deposition Parameters ◽  
Stage Process

This work reports results concerning the effect of the deposition parameters on the structural properties of Cu2ZnSnSe4 thin films, grown through a chemical reaction of the metallic precursors via coevaporation in a three-stage process. X-ray diffraction measurements revealed that the samples deposited by selenization of Cu and Sn grow in the Cu2Se and SnSe2 phases, respectively. The effect of deposition temperature and Cu/Se mass ratio on the transport properties of Cu2ZnSnSe4 films was analyzed. The electrical behavior of the compound was studied.

scholarly journals Synthesis and Characterization of Lithium Iron Phosphate Carbon Composite (LFP/C) using Magnetite Sand Fe3O4

2020 ◽  
Vol 9 (1) ◽  
pp. 16-22
Author(s):  
Zuffa Anisa ◽  
◽  
Mochammad Zainuri ◽  
Keyword(s):  
Lithium Iron Phosphate ◽  
Iron Phosphate ◽  
Solid State Reaction Method ◽  
Rietveld Analysis ◽  
Structural Features ◽  
Carbon Composite ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
Hematite Fe2o3

Lithium Ferro Phosphate Carbon Composite (LFP/C) had been synthesized using solid-state reaction method. Magnetite sand Fe3O4 was used as Fe- source in LFP/C synthesized. Calcination temperature of the sample performed at 400, 500, and 600°C. The phase and composition of samples determined by Rietveld analysis of X-ray diffraction (XRD) pattern. The dominant identified phase at 400°C was diphosphate LiFeP2O7, and the others phases were nasicon Li3Fe2(PO4)3 and hematite Fe2O3. As the temperature getting higher the diphosphate phase LiFeP2O7 transform to nasicon Li3Fe2(PO4)3.The chemical bonds, lattice vibration and other structural features of the sample were investigated using FTIR spectroscopy in range of 1400 – 400 cm-1. Specific vibration modes in LFP-1 to LFP-3 for each bonding were shown by the high intense in certain wavenumber.

Continuous flow supercritical water synthesis and crystallographic characterization of anisotropic boehmite nanoparticles

2010 ◽  
Vol 43 (4) ◽  
pp. 858-866 ◽  
Author(s):  
Nina Lock ◽  
Peter Hald ◽  
Mogens Christensen ◽  
Henrik Birkedal ◽  
Bo Brummerstedt Iversen
Keyword(s):  
Supercritical Water ◽  
Continuous Flow ◽  
X Ray Diffraction ◽  
Large Size ◽  
Transmission Electron ◽  
Boehmite Nanoparticles ◽  
Crystallite Sizes ◽  
Full Conversion ◽  
Good Agreement

Crystalline boehmite nanoparticles have been prepared in a few minutes from thermal decomposition of aluminium nitrate in near- and supercritical water. Highly anisotropic nanoparticles are formed under continuous flow conditions using T-piece mixing and a large size tube diameter. The shapes and sizes of the synthesized nanocrystals were determined from peak shape analysis of powder X-ray diffraction data. The crystallite morphology is pressure dependent, and the size increases with temperature for constant reaction time and pressure. The modelled crystallite sizes and anisotropic shapes are in good agreement with transmission electron microscopy studies. At lower synthesis pressures the boehmite crystallite morphology is a mixture of platelets and bar-shaped crystals. The bar-shaped crystals align into polycrystalline fibre-like long thin needles, which again align sidewise in bundles. At higher pressures, only the polycrystalline fibres are formed. Full conversion of dried boehmite to γ-Al2O3is observed after short-term heating to 773 K with an overall conservation of the morphology.

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