scholarly journals Свойства синтезированных методом пиролиза ультразвуковой аэрозоли наночастиц MgFe-=SUB=-2-=/SUB=-O-=SUB=-4-=/SUB=- для биомедицинских применений

2019 ◽  
Vol 61 (6) ◽  
pp. 1175
Author(s):  
А.С. Камзин ◽  
А.А. Валиуллин ◽  
В.Г. Семенов ◽  
Harinarayan Das ◽  
Naoki Wakiya
Keyword(s):  
Spin Structure ◽  
Single Phase ◽  
Spherical Particles ◽  
Magnesium Ferrite ◽  
Hyperthermia Therapy ◽  
Canted Spin ◽  
Primary Particles ◽  
Average Size ◽  
Superparamagnetic State ◽  
Ferrite Spinel

AbstractWe present the data of studies on the structure, phase states, and magnetic properties of magnetic nanoparticles (MNPs) of magnesium ferrite spinel (MgFe_2O_4), synthesized by ultrasonic aerosols pyrolysis. Primary single-phase MNPs with an average size of 9.6, 11.5, and 14.0 nm, synthesized from precursors at concentrations of 0.06, 0.12, and 0.24 M, respectively, agglomerate into tightly aggregated spherical particles (secondary particles) with sizes of 206, 300, and 340 nm, respectively. Primary particles inside the spheres do not interact with each other and are in a superparamagnetic state. There is a layer on the surface of the particles, the magnetic structure of which differs from the structure of the inner part of the MNP; this is explained by the formation of a canted spin structure or a spin glass state in the surface layer of the MNPs. MgFe_2O_4 nanospheres obtained from a precursor at a concentration of 0.06 M are most promising as valid sources of heat in magnetic hyperthermia therapy.

Low-voltage EDS of magnesium ferrite Dendrites in a FEG-SEM

1996 ◽  
Vol 54 ◽  
pp. 478-479
Author(s):  
Matthew T. Johnson ◽  
Ian M. Anderson ◽  
Jim Bentley ◽  
C. Barry Carter
Keyword(s):  
Monte Carlo ◽  
Quantitative Analysis ◽  
Monte Carlo Simulations ◽  
Cross Section ◽  
Spatial Resolution ◽  
Low Voltage ◽  
Magnesium Ferrite ◽  
X Ray ◽  
Interaction Volume ◽  
Ferrite Spinel

Energy-dispersive X-ray spectrometry (EDS) performed at low (≤ 5 kV) accelerating voltages in the SEM has the potential for providing quantitative microanalytical information with a spatial resolution of ∼100 nm. In the present work, EDS analyses were performed on magnesium ferrite spinel [(MgxFe1−x)Fe2O4] dendrites embedded in a MgO matrix, as shown in Fig. 1. spatial resolution of X-ray microanalysis at conventional accelerating voltages is insufficient for the quantitative analysis of these dendrites, which have widths of the order of a few hundred nanometers, without deconvolution of contributions from the MgO matrix. However, Monte Carlo simulations indicate that the interaction volume for MgFe2O4 is ∼150 nm at 3 kV accelerating voltage and therefore sufficient to analyze the dendrites without matrix contributions.Single-crystal {001}-oriented MgO was reacted with hematite (Fe2O3) powder for 6 h at 1450°C in air and furnace cooled. The specimen was then cleaved to expose a clean cross-section suitable for microanalysis.

scholarly journals Study on Structure, Thermal Behavior, and Viscoelastic Properties of Nanodiamond-Reinforced Poly (vinyl alcohol) Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1426
Author(s):  
Tomáš Remiš ◽  
Petr Bělský ◽  
Tomáš Kovářík ◽  
Jaroslav Kadlec ◽  
Mina Ghafouri Azar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Analysis ◽  
Single Step ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Primary Particles ◽  
Solution Casting Method ◽  
Average Size

In this work, advanced polymer nanocomposites comprising of polyvinyl alcohol (PVA) and nanodiamonds (NDs) were developed using a single-step solution-casting method. The properties of the prepared PVA/NDs nanocomposites were investigated using Raman spectroscopy, small- and wide-angle X-ray scattering (SAXS/WAXS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). It was revealed that the tensile strength improved dramatically with increasing ND content in the PVA matrix, suggesting a strong interaction between the NDs and the PVA. SEM, TEM, and SAXS showed that NDs were present in the form of agglomerates with an average size of ~60 nm with primary particles of diameter ~5 nm. These results showed that NDs could act as a good nanofiller for PVA in terms of improving its stability and mechanical properties.

scholarly journals Influence of reducing agents and surfactants on size and shape of silver fine powder particles

2014 ◽  
Vol 20 (2) ◽  
pp. 73-88 ◽  
Author(s):  
Stevan P. Dimitrijević ◽  
Željko Kamberović ◽  
Marija Korać ◽  
Zoran Anđić ◽  
Silvana Dimitrijević ◽  
...  
Keyword(s):  
Chemical Reduction ◽  
Nitrate Solution ◽  
Fine Powder ◽  
Production Scale ◽  
Scale Reduction ◽  
Primary Particles ◽  
Powder Particles ◽  
Different Shapes ◽  
Average Size ◽  
Scanning Electron

Silver fine powder with different shapes and sizes were prepared by chemical reduction and characterized by scanning electron microscope. In this paper was presented the method for the preparation of the fine Ag powder with particles size smaller than 2.5 µm with suitability for the mass-production scale. Reduction was performed from nitrate solution directly by vigorous stirring at room temperature by three different reduction agents, with and without presence of two dispersants. Scanning electron microscopy revealed the preferred size of the particles obtained in all experiments with aim of the protecting agent. Larger particles and wider size distribution were obtained without surfactants although with average size of about 1 µm and small quantity of larger clusters of primary particles that is out of the fine powder classification. High purity, 99.999%, of silver was obtained in every experiment. 

scholarly journals Synthesis, Characterization and Cytotoxic Activity of N-(5-indanyl(methylene)anthranilic acid(5-indanyl methylene)-hydrazide and Its Pt(II) Complex

2019 ◽  
pp. 1-12
Author(s):  
Nasser Mohammed Hosny ◽  
Lamiaa A. A. Barakat
Keyword(s):  
Cytotoxic Activity ◽  
Anthranilic Acid ◽  
Platinum Complex ◽  
Platinum Complexes ◽  
Ehrlich Ascites Carcinoma ◽  
Morphological Characterization ◽  
Spherical Particles ◽  
Spectral Techniques ◽  
Average Size

Since the discovery of the platinum based complex, cisplatin, medicinal inorganic chemistry has attracted much more attention and a large number of platinum complexes with promising pharmacological properties have been synthesized. In this work a new platinum complex of N-(5-indanyl(methylene)anthranilic acid(5-indanyl methylene)-hydrazide (HL) has been synthesized and characterized by physical and spectral techniques, as elemental analysis, IR, EI-MS, 1H-NMR, thermal analysis, transmittance electron microscope (TEM) and magnetic moment. The results indicated that the ligand binds to Pt(II) in the enol form. Square-planar stereochemistry was suggested for the Pt(II) complex. The morphological characterization showed nano-sized spherical particles with average size 92 nm of the isolated complex. The synthesized Pt(II) complex exhibited a significant cytotoxic activity against HCT116 and HEPG2. Also in vivo study of the Pt(II) complex showed cytotoxic activity towards Ehrlich ascites carcinoma (EAC).

scholarly journals The Morphology of Freeze-Dried Rubidium Chloride Powder

1989 ◽  
Vol 155 ◽  
Author(s):  
J. K. G. Panitz ◽  
J. A. Voigt ◽  
F. A. Greulich ◽  
M. J. Carr ◽  
M. O. Eatough
Keyword(s):  
Droplet Size ◽  
Freeze Drying ◽  
Low Concentrations ◽  
Aerosol Spray ◽  
Freeze Dried ◽  
Primary Particles ◽  
Ionic Compounds ◽  
Freezing Cycle ◽  
Average Size ◽  
Stock Solutions

ABSTRACTWe have formed powders of a strongly ionic compound, RbCl by freezedrying. Stock solutions, varying from very low concentrations with 4 gm RbCl reagent dissolved in 100 cc water to saturated solutions with 80 gm reagent in 100 cc water, were sprayed into isopentane at -160°C. The droplet size in the spray was varied from relatively large 4-mm diameter droplets to extremely small droplets in an aerosol spray. It was determined that both the concentration of the stock solution and the droplet size affect the average size and the size distribution of the primary particles formed and the way in which these primary particles are bonded together. Unlike the powders of many less ionic compounds that are produced by freeze-drying, the primary particles in these RbCl powders are crystalline rather than amorphous. Analysis with an x-ray diffractometer with a cold stage indicates that crystallization occurs during the freezing cycle rather than during the sublimation period of the freeze-drying process.

scholarly journals Синтез и магнитные свойства наночастиц Fe-=SUB=-3-=/SUB=-O-=SUB=-4-=/SUB=-/CoFe-=SUB=-2-=/SUB=-O-=SUB=-4-=/SUB=- со структурой ядро/оболочка

2020 ◽  
Vol 62 (2) ◽  
pp. 235
Author(s):  
Д.А. Балаев ◽  
С.В. Семенов ◽  
А.А. Дубровский ◽  
А.А. Красиков ◽  
С.И. Попков ◽  
...  
Keyword(s):  
Single Phase ◽  
Hybrid Particles ◽  
Soft Magnetic ◽  
Cofe2o4 Nanoparticles ◽  
The Core ◽  
Core Shell Structure ◽  
Magnetically Hard ◽  
Co Precipitation ◽  
Average Size ◽  
Magnetic Fe3o4

Fe3O4 / CoFe2O4 nanoparticles with a core-shell structure with an average size of 5 nm were obtained by co-precipitation from solutions of iron and cobalt chlorides. An analysis of the magnetic properties of the resulting system and their comparison with the data for single-phase Fe3O4 (4 nm) and CoFe2O4 (6 nm) nanoparticles led to the conclusion that there is a noticeable interaction between the soft magnetic (Fe3O4) and magnetically hard (CoFe2O4) phases that form the core and the shell of hybrid particles, correspondingly.

Canted Spin Structure of β1-MnZn

1966 ◽  
Vol 21 (10) ◽  
pp. 2080-2080 ◽  
Author(s):  
Tomiei Hori ◽  
Yasuaki Nakagawa ◽  
Yoshikazu Ishikawa
Keyword(s):  
Spin Structure ◽  
Canted Spin

Electrical Properties of Nanocrystalline Tungsten Trioxide

1999 ◽  
Vol 581 ◽  
Author(s):  
A. Hoel ◽  
L.B. Kish ◽  
R. Vajtai ◽  
G.A. Niklasson ◽  
C.G. Granqvist ◽  
...  
Keyword(s):  
Tungsten Trioxide ◽  
Impedance Spectrum ◽  
Ambient Air ◽  
Vapor Condensation ◽  
Smart Windows ◽  
Primary Particles ◽  
Significant Interest ◽  
Average Size ◽  
Capacitance Effects ◽  
Evaporation Unit

ABSTRACTTungsten oxide is a material of significant interest for applications in several areas. It can, for example, be used as the electrochromic film in smart windows. Tungsten trioxide nanoparticles were produced using an advanced gas evaporation unit in which the tungsten was oxidized in low pressure ambient air. The tungsten trioxide particles were formed via vapor condensation and were deposited by gas deposition technique to avoid coagulation effects. The average size of the primary particles was around 5 nm, depending on the heating power and the pressure. The particles exhibited a body centred cubic structure. The impedance spectrum of particle deposits showed resonance and negative capacitance effects. The correlation between fabrication conditions, structure and impedance spectrum is discussed.

scholarly journals Synthesis Features of Iron Oxide Nanopowders with High Magnetic and Sorption Properties

2018 ◽  
Vol 915 ◽  
pp. 116-120
Author(s):  
Sergiy Lavrynenko ◽  
Athanasios G. Mamalis ◽  
Dmitry Sofronov ◽  
Alexandra Odnovolova ◽  
Vadym Starikov
Keyword(s):  
Phase Composition ◽  
Magnetic Particles ◽  
Deposition Process ◽  
Spherical Particles ◽  
Sorptive Capacity ◽  
Extraction Separation ◽  
Average Size ◽  
Increasing Temperature ◽  
Magnetite Phase ◽  
Purification Of Water

The magnetic particles of iron oxides are promising materials for the purification of water from ions of heavy metals and radionuclides. Their advantage compared to other sorbents is the ability to extract by applied magnetic field, which greatly simplifies the task of extraction, separation and processing in cleaning technologies. The aim of this work is investigation of temperature and concentration of iron in the solution effect on the phase composition, nanoparticle size and their magnetization. Phase magnetite in the sample increases with increasing temperature and the magnetization decreases slightly with increasing the initial concentration of iron in solution. We found that regardless of the conditions of deposition formed spherical particles whose average size ranges from 7 to 15 nm. The sorptive capacity of the particles is virtually independent of the phase composition and for cobalt is about 18 mg/g. For sorption-based material magnetic particles Fe3O4 recommended to carry out the deposition process at a temperature not lower than 80°C. The concentration of iron in solution must be within 0,15–0,3M. The particles obtained contain in their composition at least 90 wt.% of magnetite phase and are characterized by a magnetization in the range of 65–70 A·m2/kg. Also in the paper is comparing efficiency of extraction and sorption capacity for cobalt particles by different phase of magnetite and hematite.

scholarly journals Prediction of Strength and Ductility in Partially Recrystallized CoCrFeNiTi0.2 High-Entropy Alloy

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 389 ◽  
Author(s):  
Hanwen Zhang ◽  
Peizhi Liu ◽  
Jinxiong Hou ◽  
Junwei Qiao ◽  
Yucheng Wu
Keyword(s):  
Tensile Strength ◽  
Single Phase ◽  
Volume Fraction ◽  
Tensile Elongation ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Number Density ◽  
High Entropy ◽  
Average Size ◽  
Strength And Ductility

The mechanical behavior of a partially recrystallized fcc-CoCrFeNiTi0.2 high entropy alloys (HEA) is investigated. Temporal evolutions of the morphology, size, and volume fraction of the nanoscaled L12-(Ni,Co)3Ti precipitates at 800 °C with various aging time were quantitatively evaluated. The ultimate tensile strength can be greatly improved to ~1200 MPa, accompanied with a tensile elongation of ~20% after precipitation. The temporal exponents for the average size and number density of precipitates reasonably conform the predictions by the PV model. A composite model was proposed to describe the plastic strain of the current HEA. As a consequence, the tensile strength and tensile elongation are well predicted, which is in accord with the experimental results. The present experiment provides a theoretical reference for the strengthening of partially recrystallized single-phase HEAs in the future.

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