Yttrium nanoparticles

Second, crystallographic engineering of the top atomic layer of the cores allows us to anploy a variety of core materials and so modification of the properties of supported PtML- Electrodeposition in nonaqueous solvents may open a fundamentally distinct area for the design and synthesis of core-shell nanoparticles. Considerable possibilities arise for studying core-shell interactions that are inaccessible in aqueous solutions. Our preliminary data show that yttrium nanoparticles, electro-deposited on carbon black in an organic solution, exhibited a certain unique interaction with codeposited Pt a 10-fold lower concentration of such Pt does not affect much the cathodic peak while it suppresses the dissolution of yttrium at the anode. On the other hand, we propose that carbon quantum dots, for example, small fragments of graphene oxides or carbon nanotubes, can support a... 

The sacrificial core approach entails depositing a coating on the surface of particles by either the controlled surface precipitation of inorganic molecular precursors from solution or by direct surface reactions [2,3,5,6,8,9,33-35,38], followed by removal of the core by thermal or chemical means. Using this approach, micron-size hollow capsules of yttrium compounds [2], silica spheres [38], and monodisperse hollow silica nanoparticles [3,35] have been generated. 

Y203 Eu nanoparticles for potential use in FEDs have been prepared in nonionic reverse microemulsions.124 The particles were synthesized by the reaction between aqueous yttrium nitrate, europium nitrate, and ammonium hydroxide, by bulk precipitation in the reverse microemulsion... 

Since oxide materials are extensively used in practical devices such as lamp phosphors or laser materials, their behavior at the nanoscale level has also been investigated. The size of yttrium oxide nanoparticles Y2C>3 Ln can be finely tuned by glycine-nitrate combustion synthesis. The overall equation of the exothermic reaction can be expressed as ... 

Yttrium orthoborate nanoparticles Yi xNdxB03 have been less studied. They can be prepared by hydrothermal synthesis from boric acid, urea, yttrium nitrate, and neodymium... 

Case e Nanoparticles formation was observed, for example, in the case of Yttrium, Samarium, Neodimium and Gadolinium acetates (superconductor precursors) and in the case of Dextran (polymer). Tetracycline (antibiotic) and other compounds. This morphology was obtained at COj densities larger than those characteristic of case d. Nanoparticles down to a mean diameter of 50 nm were obtained in the case of Zinc acetate (catalyst precursor). Microparticles as well as nanoparticles were obtained for Amoxicillin, Rifampicin (antibiotic) (Figure 4) and other compounds. 

In a similar work, ultrasound radiation was used to prepare EU2O3 doped in zir-conia and yttrium-stabilized zirconium (YSZ) nanoparticles [83]. Europium oxide was also coated sonochemically on the surface of submicron spherical zirconia and YSZ, which were fabricated by wet chemical methods. Time decay measurements of the doped and coated materials were conducted using a pulsed laser source. Lifetimes < 1.1 ms radiative lifetime of the Eu+ ions were detected for the doped and coated as-prepared materials. When the doped and coated samples were an-... 

The size of the nanodroplets can be controlled in the range of 5 - 80 nm by changing the concentration ratio of water/surfactant in the microemulsion system. By this method, yttrium oxide [67], cerium oxide [68-70], neodymium oxide [71], and erbium oxide [72, 73] nanoparticles have been synthesized. The average particle size of the particles adopts values in the range fi om 2 to 70 nm, which depends on the synthesis conditions. 

Lamellar nanohybrids composed of Ln203 layers regularly separated from each other by organic layers of intercalated benzoate molecules can be obtained by a one-pot procedure (Karmaoui et al., 2006), the benzyl alcohol route. Lanthanide isopropoxides are simply dissolved in benzyl alcohol and reacted at high temperature (250-300 °C), resulting in the isolation of nanoparticles of 50-nm mean size. Eu -doped nanohybrids have better radiance characteristics than the standard phosphor Y203 Eu while both yttrium- and gadolinium-based nanomaterials doped with Nd display intense NIR luminescence, with a Nd( F3/2) lifetime of 49 ps in the case of the yttrium nanohybrid (Sa Ferreira et al., 2006). 

Yu F, Yuan D, Cheng X, Duan X, Wang X, Kong L et al (2007) Preparation and characterization of yttrium gallium garnet nanoparticles by citrate sol-gel method at low temperature. Mater Lett 61 2322—2324... 

At very large expansion levels (asymptotic expansion) nanoparticles are produced by balloons disintegration. An example of yttrium acetate nanoparticles is reported in Figure 24.8. These particles are very small (100-200 nm) and have a very narrow particle size distribution [18]. 

FIGURE 24.8 SEM image of yttrium acetate nanoparticles precipitated from DMSO (15 mg/ml) at 120 bar and 313 K, with mean diameters of about 150 nm. (Reprinted from Reverchon, E., J. Supercrit. Fluids, 15, 1-21, 1999. With permission from Elsevier.)... 

Typical ferroelastic is zirconia, which can be obtained from the unstable compounds in the form of powders. As a result of calcination of zirconium oxalate or hydroxide under non-isothermal conditions, the extreme dependence of the specific surface area of zirconia nanoparticles on heating rate has been revealed. This dependence has been confirmed for both pure Zr02 and stabilized with different dopants (Fig. 5.21). In accordance with [301], the maximum surface area for the amorphous powders of yttrium stabilized zirconia with particle size less than 5 nm, growing during crystallization and coarsening to 8-10 nm, depends on the heating mode. 

Hirai T, Orikoshi T. Preparation of yttrium oxysulfide phosphor nanoparticles with inffared-to-green and -blue upconversion emission using an emulsion liquid membrane system. J Colloid Interface Sci 2004 273(2) 470. 

Another investigation of Lee et al. [290] used the same two-microemulsion technique for the preparation of Eu Y203 particles, i.e. mixing of two microemulsions containing NP-5/NP-9 surfactants (20 wt%), cyclohexane (62 wt%) and aqueous solution (18%) of either (i) yttrium and europium nitrate hydrates or (ii) ammonia. The products gathered after breaking of the mixed microemulsions were calcined at 900°C to obtain nanoparticles (spherical, 20-30 nm agglomerates). The steps therefore are ... 

The groups of Song and Zhang et al. have used a combination of a sol-gel method and arrested precipitation to prepare nanocrystalline Y203-based upconverters [15,16]. They first prepared a gel from yttrium and lanthanide nitrates and ammonia hydroxide that was arrested by citrate ligands. Then, they calcinated the dried gel at 800°C and obtained upconverting nanocrystalline material. It has to be stated that methods that involve annealing/calcination always result in nanocrystalline material rather than colloidally stable nanoparticles. 

Schubert D, Dargusch R, Raitano J et al (2006) Cerium and yttrium oxide nanoparticles are neuroprotective. Biochem Biophys Res Commun 342 86—91... 

MW-Assisted Synthesis of Bisubstituted Yttrium Carnet Nanoparticles... 

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