Abstract P-7: NdFeCo-based Nanoparticles for Biomedical Applications

Background: The multifunctional nanoparticles can be promising antitumor materials. The results of a study of synthesized NdFeCoB oxide nanoparticles (NPs) as a basis for drug transportation systems are presented. In the next step, the NPs can be coated by a multifunctional gel shell. Methods: NPs, the composition of NdFexCo1-xB (where x =0, 0.05, 0.1, 0.2, 0.3, 0.4, and 0.5), were synthesized by a Pechini-type sol-gel method. The synthesis allows tuning of NPs magnet properties by manipulating the microstructure and phase composition. NPs were studied by XRD, SEM, TEM, HRTEM, and VSM. Results: SEM images show that the average size of NPs changed from 280 nm (for x = 0) up to 416 nm (for x = 0.1 – 0.5). At TEM images the NPs of the sample without cobalt (x = 0) have an elongated shape (Fig 1a). Diffraction patterns showed that the NPs consist of single crystal or ordered crystallites. NPs with cobalt mainly consist of crystallites with a size of about 20-50 nm. There are also areas with a complex-grained microstructure. Hysteresis loops and first-order reversal curve analysis indicated that the NPs were ferromagnetic whose coercivity, squareness ratio, and magnetic interactions changed significantly with the cobalt contents.

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Upconversion Luminescence of Silica–Calcia Nanoparticles Co-doped with Tm3+ and Yb3+ Ions

Materials ◽

10.3390/ma14040937 ◽

2021 ◽

Vol 14 (4) ◽

pp. 937

Author(s):

Katarzyna Halubek-Gluchowska ◽

Damian Szymański ◽

Thi Ngoc Lam Tran ◽

Maurizio Ferrari ◽

Anna Lukowiak

Keyword(s):

Energy Transfer ◽

Near Infrared ◽

Upconversion Luminescence ◽

Sol Gel ◽

Emission Spectra ◽

Transmission Electron ◽

Characteristic Emission ◽

Diffraction Patterns ◽

Size Of Particles ◽

Average Size

Looking for upconverting biocompatible nanoparticles, we have prepared by the sol–gel method, silica–calcia glass nanopowders doped with different concentration of Tm3+ and Yb3+ ions (Tm3+ from 0.15 mol% up to 0.5 mol% and Yb3+ from 1 mol% up to 4 mol%) and characterized their structure, morphology, and optical properties. X-ray diffraction patterns indicated an amorphous phase of the silica-based glass with partial crystallization of samples with a higher content of lanthanides ions. Transmission electron microscopy images showed that the average size of particles decreased with increasing lanthanides content. The upconversion (UC) emission spectra and fluorescence lifetimes were registered under near infrared excitation (980 nm) at room temperature to study the energy transfer between Yb3+ and Tm3+ at various active ions concentrations. Characteristic emission bands of Tm3+ ions in the range of 350 nm to 850 nm were observed. To understand the mechanism of Yb3+–Tm3+ UC energy transfer in the SiO2–CaO powders, the kinetics of luminescence decays were studied.

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Mechanical Properties of Chitosan-Starch Composite Filled Hydroxyapatite Micro- and Nanopowders

Journal of Nanomaterials ◽

10.1155/2011/391596 ◽

2011 ◽

Vol 2011 ◽

pp. 1-5 ◽

Cited By ~ 8

Author(s):

Jafar Ai ◽

Mostafa Rezaei-Tavirani ◽

Esmaeil Biazar ◽

Saeed Heidari K ◽

Rahim Jahandideh

Keyword(s):

Sol Gel ◽

Weight Ratio ◽

Tensile Modulus ◽

Mechanical Analysis ◽

Sem Images ◽

Chitosan Hydrogel ◽

Size Particle ◽

Average Size ◽

Hard Tissue Engineering ◽

Nano Size

Hydroxyapatite is a biocompatible ceramic and reinforcing material for bone implantations. In this study, Starch-chitosan hydrogel was produced using the oxidation of starch solution and subsequently cross-linked with chitosan via reductive alkylation method (weight ratio (starch/chitosan): 0.38). The hydroxyapatite micropowders and nanopowders synthesized by sol-gel method (10, 20, 30, 40 %W) were composited to hydrogels and were investigated by mechanical analysis. The results of SEM images and Zetasizer experiments for synthesized nanopowders showed an average size of 100 nm. The nanoparticles distributed as uniform in the chitosan-starch film. The tensile modulus increased for composites containing hydroxyapatite nano-(size particle: 100 nanometer) powders than composites containing micro-(size particle: 100 micrometer) powders. The swelling percentage decreased for samples containing hydroxyapatite nanopowder than the micropowders. These nanocomposites could be applied for hard-tissue engineering.

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Enhanced Magnetic Properties of Co-Doped BiFeO3 Thin Films via Structural Progression

Nanomaterials ◽

10.3390/nano10091798 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1798

Author(s):

Liang Bai ◽

Mingjie Sun ◽

Wenjing Ma ◽

Jinghai Yang ◽

Junkai Zhang ◽

...

Keyword(s):

Thin Films ◽

Magnetic Properties ◽

Sol Gel ◽

Sem Images ◽

Size Mismatch ◽

Structural Progression ◽

Gel Technique ◽

Average Size ◽

Perovskite Lattice ◽

Co Doped

Co3+ doping in BiFeO3 is expected to be an effective method for improving its magnetic properties. In this work, pristine BiFeO3 (BFO) and doped BiFe1-xCoxO3 (BFCxO, x = 0.01, 0.03, 0.05, 0.07 and 0.10) composite thin films were successfully synthesized by a sol–gel technique. XRD and Raman spectra indicate that the Co3+ ions are substituted for the Fe3+ ion sites in the BFO rhombohedral lattice. Raman vibration of oxygen octahedron is obviously weakened due to the lattice distortion induced by the size mismatch between two B-site cations (Fe3+ and Co3+ ions), which has an impact on the magnetic properties of BFCxO. SEM images reveal a denser agglomeration in Co-doped samples. TEM results indicate that the average size of grains is reduced due to the Co3+ substitution. XPS measurements illustrate that the replacement of Fe3+ with Co3+ effectively suppresses the generation of oxygen defects and increases the concentration of Fe3+ ions at the B-site of perovskite lattice. Vibrating sample magnetometer (VSM) measurements show that the remanent magnetization (Mr) of BFC0.07O (3.6 emu/cm3) and the saturation magnetization (Ms) of BFC0.10O (48.84 emu/cm3) thin film both increase by approximately two times at room temperature, compared with that of the pure BFO counterpart.

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Homogeneity in the Polyether Alkoxide Sol‐Gel Synthesis of YBa2Cu3O7-δ

MRS Proceedings ◽

10.1557/proc-346-29 ◽

1994 ◽

Vol 346 ◽

Cited By ~ 1

Author(s):

Carol S. Houk ◽

Gary A. Burgoine ◽

Catherine J. Page

Keyword(s):

Sol Gel ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Diffraction Patterns ◽

Mapping Techniques ◽

Starting Solutions ◽

Average Size ◽

Sol Gel Synthesis ◽

Elemental Maps

ABSTRACTWe have investigated the homogeneity of sol‐gel derived YBa2Cu307‐s from the solution phase to the final product using transmission electron microscopy (TEM), x‐ray diffraction (XRD), and Energy Dispersive X‐ray (EDX) lateral mapping techniques. The starting solutions contain stoichiometric amounts of the metal 2‐(2‐methoxyethoxy)ethoxide components in 2‐(2‐methoxyethoxy)ethanol and appear to be homogeneous by TEM with a uniform distribution of particles having an average size of less than 40 â. Through elemental mapping we see elemental segregation in the high temperature (950 °C) products, which are orthorhombic by XRD. In elemental maps of gel samples fired to 700 °C, which are tetragonal by XRD, we also see elemental inhomogeneity within particles and phase zoning in maps of products from finely ground gels. A comparison of elemental maps and x‐ray diffraction patterns of the products from gel processing and conventional solid state processing is made.

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Production of Syngas by Combination of CO2 Reforming and Partial Oxidation of CH4 over Ni/Al2O3 Catalysts in Fixed-bed Reactor

International Journal of Chemical Reactor Engineering ◽

10.2202/1542-6580.2114 ◽

2010 ◽

Vol 8 (1) ◽

Cited By ~ 3

Author(s):

Mohammad Zangouei ◽

Abdolsamad Zarringhalam Moghaddam ◽

Abdolhosein Razeghi ◽

Mohammad Reza Omidkhah

Keyword(s):

Partial Oxidation ◽

Sol Gel ◽

Fixed Bed ◽

Fixed Bed Reactor ◽

Sem Images ◽

Co2 Reforming ◽

Syngas Production ◽

Oxidation Of Methane ◽

Filamentous Carbon ◽

Diffraction Patterns

Ni/Al2O3 catalysts were synthesized by sol-gel method with various nickel loadings. Chemical and physical properties of the catalysts were characterized by XRD and TPR techniques. X-ray diffraction patterns showed no peaks due to NiO species. Temperature-programmed reduction (TPR) indicated that the nickel species mainly presented in NiAl2O4 phase. The effect of nickel loading on the catalytic activity of Ni/Al2O3 catalysts, selectivity of products, yield of hydrogen production and H2/CO ratio was investigated in the combination of dry reforming and partial oxidation of methane (DRPOM) reaction. The results indicated that these parameters are greatly dependent on the amount of nickel loading. The results also revealed that the catalyst with 20 percent nickel loading had the highest activity for syngas production after 270 min reaction on stream. The SEM images of spent catalysts showed the formation of filamentous carbon on the 20Ni/Al and 30Ni/Al catalysts.

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LiCoO2 Cathode Material Coated with Nano-Crystallized ZnO by Sol-Gel Method

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.280-283.665 ◽

2007 ◽

Vol 280-283 ◽

pp. 665-670

Author(s):

Jye Hwa Wang ◽

Ting Fang ◽

Jenq Gong Duh

Keyword(s):

Cathode Material ◽

Sol Gel ◽

Surface Region ◽

Sem Images ◽

Gel Method ◽

Sol Gel Method ◽

Cathode Degradation ◽

Before And After ◽

Morphological Differences ◽

Average Size

LiCoO2 spinel is one of the most promising cathode materials for Li-ion batteries. However, the capacity fading is aggravated at high voltage, resulting from cathode degradation and electrolyte decomposition owing to over-charging. To improve structural stability, surface modification is an effective method. In this study, nano-crystallized ZnO was coated on the surface of commercial LiCoO2 powders via sol-gel method. The correlation among the amount of coated ZnO, microstructure of modified cathode and the cycling behavior of surface-treated LiCoO2 powders is discussed. Moreover, the effects of cycling for cathodes with as-derived powders on the phase and morphology are also considered. The surface morphology observed from the scanning electron microscope (SEM) images shows that nano-crystallized and spherical ZnO particles with an average size of about 20 nm have developed after coating. The size of ZnO nanocrystallites is related to the initial concentration of Zn2+ cations. In comparing the characteristics of bare and coated LiCoO2 powders, improvement in cyceability of the ZnO-coated cathode is explored. It is confirmed that Zn2+ ions diffuse into the surface region of LiCoO2 particles. To reveal the effects of Zone coating on enhancing the electrochemical properties of LiCoO2 cathode during charge and discharge, the morphological differences between the cathode material before and after cycling are discussed.

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Identification by Electron Microdiffraction of Intermetallic Phases in a Duplex Stainless Steel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100136076 ◽

1990 ◽

Vol 48 (2) ◽

pp. 494-495

Author(s):

A. Redjaïmia ◽

J.P. Morniroli ◽

G. Metauer ◽

M. Gantois

Keyword(s):

Stainless Steel ◽

Duplex Stainless Steel ◽

Convergent Beam Electron Diffraction ◽

Intermetallic Phases ◽

Small Particles ◽

Parallel Beam ◽

Diffraction Patterns ◽

Average Size ◽

Convergent Beam ◽

Electron Microdiffraction

2D and especially 3D symmetry information required to determine the crystal structure of four intermetallic phases present as small particles (average size in the range 100-500nm) in a Fe.22Cr.5Ni.3Mo.0.03C duplex stainless steel is not present in most Convergent Beam Electron Diffraction (CBED) patterns. Nevertheless it is possible to deduce many crystal features and to identify unambiguously these four phases by means of microdiffraction patterns obtained with a nearly parallel beam focused on a very small area (50-100nm).From examinations of the whole pattern reduced (RS) and full (FS) symmetries the 7 crystal systems and the 11 Laue classes are distinguished without ambiguity (1). By considering the shifts and the periodicity differences between the ZOLZ and FOLZ reflection nets on specific Zone Axis Patterns (ZAP) which depend on the crystal system, the centering type of the cell and the glide planes are simultaneously identified (2). This identification is easily done by comparisons with the corresponding simulated diffraction patterns.

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