Facile Synthesis and Luminescence Properties of Gd2O3:Eu3+ Hollow Spheres

2014 ◽  
Vol 998-999 ◽  
pp. 55-58
Author(s):  
Cui Miao Zhang ◽  
Jian Yuan Wang ◽  
Ya Min Liu ◽  
Guang Jia
Keyword(s):  
Hollow Spheres ◽  
Hollow Structure ◽  
Spherical Shape ◽  
Precipitation Method ◽  
Main Process ◽  
Flat Panel Displays ◽  
Light Emitting ◽  
Potential Applications ◽  
Biological Labeling ◽  
Aqueous Conditions

Well-dispersed, uniform Gd2O3:Eu3+ hollow microspheres have been successfully fabricated via a urea-based homogeneous precipitation method in the presence of colloidal carbon spheres as template, followed by subsequent heat treatment. The main process was carried out under aqueous conditions without any organic solvents, surfactants, or etching agents. The as-obtained Gd2O3:Eu3+ spheres with a spherical shape and hollow structure are uniform in size and distribution, and the diameters of the spheres and thickness of the shell are about 500 nm and 50 nm, respectively. The Gd2O3:Eu3+ hollow spheres exhibit strong red emission corresponding to the 5D0-7F2 transition of the Eu3+ ions under ultraviolet excitation, which might find potential applications in the fields such as light-emitting phosphors, advanced flat panel displays, or biological labeling.

Template-Directed Synthesis and Upconversion Luminescence of Y2O3 Hollow Spheres

2014 ◽  
Vol 1052 ◽  
pp. 198-202 ◽  
Author(s):  
Cui Miao Zhang ◽  
Jian Yuan Wang ◽  
Ya Min Liu ◽  
Guang Jia
Keyword(s):  
Upconversion Luminescence ◽  
Hollow Spheres ◽  
Spherical Shape ◽  
Hollow Microspheres ◽  
Flat Panel Displays ◽  
Sem Images ◽  
Calcination Process ◽  
Potential Applications ◽  
Subsequent Calcination ◽  
Light Excitation

Uniform Y2O3 hollow microspheres have been successfully prepared via a urea-based homogeneous precipitation technique with colloidal carbon spheres as template followed by a subsequent calcination process. The template can be effectively removed and the amorphous precursor has converted to crystalline Y2O3 during the annealing process. SEM images indicate that the hollow spheres inherit the spherical shape and good dispersion of the templates, and the shell of the hollow spheres is composed of a large amount of uniform nanoparticles. The lanthanide activator ion Ln3+-doped Y2O3 hollow microspheres exhibit bright upconversion luminescence with different colors under 980 nm light excitation, which may find potential applications in the fields such as light phosphor powders, advanced flat panel displays, or drug delivery.

Preparation of hollow Fe3O4 spheres through a facile method and their applications

2017 ◽  
Vol 10 (06) ◽  
pp. 1750075 ◽  
Author(s):  
Xingping Wu ◽  
Aiping Zhu ◽  
Zhaodong Nan
Keyword(s):  
Saturation Magnetization ◽  
Ostwald Ripening ◽  
Solvothermal Method ◽  
Hollow Spheres ◽  
Hollow Structure ◽  
Solid Sphere ◽  
Small Particles ◽  
Potential Applications ◽  
One Step ◽  
Solid Spheres

Fe3O4 hollow microspheres with good dispersibility and high saturation magnetization were synthesized through a facile one-step solvothermal method. The formation mechanism of the hollow structure was studied by taking time-dependent experiments. Porous [Formula: see text]-FeOOH and [Formula: see text]-Fe2O3 nanosheets were firstly fabricated. Fe3O4 solid spheres aggregated by small particles were obtained from the transition of [Formula: see text]-FeOOH and [Formula: see text]-Fe2O3. Finally, the solid sphere is transferred to hollow sphere through Ostwald ripening. The maximum saturation magnetization of the hollow spheres is [Formula: see text][Formula: see text]emu/g, which is higher than some results reported in references. The Fe3O4 hollow spheres show potential applications in microwave absorption and photocatalysis.

Planarization of Deep Structures Using Self-Leveling Materials

2012 ◽  
Vol 2012 (1) ◽  
pp. 000079-000083
Author(s):  
Dongshun Bai ◽  
Michelle Fowler ◽  
Curtis Planje ◽  
Xie Shao
Keyword(s):  
Integrated Circuits ◽  
Microelectromechanical Systems ◽  
Flat Panel Displays ◽  
New Materials ◽  
Flat Panel ◽  
Light Emitting ◽  
Good Thermal Stability ◽  
Device Integration ◽  
Potential Applications ◽  
Processing Steps

To achieve device integration that will allow the manufacture of smaller, more functional, and more efficient microelectronics, the industry increasingly requires materials to fill and planarize devices with deep structures. Brewer Science has developed several new self-leveling materials to address these planarization needs. These newly developed materials are designed to be either temporary materials that can be removed after their use in processing steps or permanent materials that can stay in a device for its lifetime. These new materials can be applied easily by means of a spin-coating process. They are unique because they can fill and planarize high-aspect-ratio trenches and vias hundreds of microns deep. Some of the materials are photosensitive and can be patterned using photolithography. All of the photosensitive materials in this paper can be developed with industry-accepted solvents and some with an aqueous TMAH solution. Because of their good thermal stability, high transparency, and excellent planarization properties, these materials have potential applications for microelectromechanical systems (MEMS), 3-D integrated circuits, light-emitting diodes (LEDs), semiconductors, flat-panel displays, and related microelectronic and optoelectronic devices. This paper will discuss the properties of these new materials and will present the filling and leveling results obtained in several applications.

scholarly journals BIODEGRADABLE GELATIN DECORATED Fe3O4 NANOPARTICLES FOR PACLITAXEL DELIVERY

2018 ◽  
Vol 55 (1B) ◽  
pp. 7 ◽  
Author(s):  
Dai Hai Nguyen
Keyword(s):  
Fe3o4 Nanoparticles ◽  
Drug Loading ◽  
Spherical Shape ◽  
Average Diameter ◽  
Precipitation Method ◽  
Loop Analysis ◽  
Transmission Electron ◽  
Potential Applications ◽  
Size And Morphology ◽  
Co Precipitation

The objective of this study is to prepare biodegradable iron oxide nanoparticles with gelatin (GEL) for paclitaxel (PTX) delivery. In detail, Fe3O4 nanoparticles were prepared and then coated them with GEL (Fe3O4@GEL) conjugate by co–precipitation method. Furthermore, the formation of Fe3O4@GEL was demonstrated by Fourier transform infrared (FT–IR) and powder X–ray diffraction (XRD). The superparamagnetic property of Fe3O4@GEL was also showed by hysteresis loop analysis, the saturation magnetization reached 20.36 emu.g–1. In addition, size and morphology of Fe3O4@GEL nanoparticles were determined by transmission electron microscopy (TEM). The results indicated that Fe3O4@GEL nanoparticles were spherical shape with average diameter of 10 nm. Especially, PTX was effectively loaded into the coated magnetic nanoparticles, 86.7 ± 3.2 % for drug loading efficiency and slowly released up to 5 days. These results suggest that the potential applications of Fe3O4@GEL nanoparticles in the development of stable drug delivery systems for cancer therapy.

Synthesis of Hollow ß-Phase GeO2 in Microemulsion

2013 ◽  
Vol 669 ◽  
pp. 360-365
Author(s):  
Xu Zou ◽  
Bing Bing Liu ◽  
Wei Wu ◽  
Dong Mei Li ◽  
Quan Jun Li ◽  
...  
Keyword(s):  
Optical Properties ◽  
Ostwald Ripening ◽  
Hollow Structure ◽  
Simple Method ◽  
Light Emitting ◽  
Hollow Interior ◽  
Potential Applications ◽  
One Step ◽  
Average Size ◽  
20 Nm

We fabricated mono-dispersed hollow waxberry shaped ß-quartz GeO2by a facile one-step synthesis in emulsion at room temperature. TEM images indicated that hollow waxberry shaped GeO2were consisted of nano-sphere whose average size were estimated to be 20 nm. The growth mechanism and optical properties of the products were also investigated. The possible formation mechanism of the hollow interior is proposed as the Ostwald ripening. The optical properties of the ß-GeO2nanoparticles with hollow shapes were also studied with photoluminescence spectrum, which reveals a broad emission, suggesting potential applications in electronic and optoelectronic nanodevices. These attractive results provide us a new simple method further used to fabricate other specific hollow structure and indicate hollow waxberry shaped GeO2may have potential applications in light-emitting nanodevices.

Uniform and Well-Dispersed LuBO3 Hollow Microspheres: Synthesis, Formation and Photoluminescence Properties

2018 ◽  
Vol 18 (12) ◽  
pp. 8302-8306 ◽  
Author(s):  
Yu Gao ◽  
Baotong Xu ◽  
Feixue Ai ◽  
Guiyan Zhao ◽  
Yanfeng Bi ◽  
...  
Keyword(s):  
Uv Light ◽  
Exchange Process ◽  
Hollow Spheres ◽  
Average Diameter ◽  
Hollow Microspheres ◽  
Precipitation Method ◽  
Ion Exchange Process ◽  
Potential Applications ◽  
First Time ◽  
Display Systems

A hard template strategy is developed to fabricate the LuBO3: Eu3+/Tb3+ hollow microspheres using a novel multi-step transformation synthetic route for the first time with polystyrene (PS) spheres as the template, followed by the combination of a facile homogeneous precipitation method, an ion-exchange process, and a calcination process. The results show that the as-obtained LuBO3: Eu3+/Tb3+ hollow spheres have a uniform morphology with an average diameter of 1.8 μm and shell thickness of about 80 nm. When used as luminescent materials, the emission colors of LuBO3: Eu3+/Tb3+ samples can be tuned from red, through orange, yellow and green–yellow, to green by simply adjusting the relative doping concentrations of the activator ions under the excitation of ultraviolet (UV) light, which might have potential applications in the field such as light display systems and optoelectronic devices.

scholarly journals Structural, Optical, Magnetic, Photocatalytic Activity and Related Biological Effects of CoFe2O4 Ferrite Nanoparticles

2021 ◽  
Author(s):  
B. Yalcin ◽  
S. Ozcelik ◽  
K. Icin ◽  
K. Senturk ◽  
B. Ozcelik ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Biological Effects ◽  
Spherical Shape ◽  
Biological Properties ◽  
Heme Iron ◽  
Morphological Properties ◽  
Precipitation Method ◽  
Sem Images ◽  
Potential Applications ◽  
Co Precipitation

Abstract The synthesis of magnetic nano-size spinel ferrites has become an important area of research, due to their several potential applications. In this work, CoFe2O4 nanoparticles were synthesized by the co-precipitation method. Structural, magnetic and photocatalytic properties of cobalt ferrites were analyzed based on their chemical composition considering their biological properties. Structural and morphological properties were investigated by X-ray diffraction analysis (XRD) and SEM respectively. Lattice parameters and cell volumes were calculated from XRD data. SEM images revealed uniform surface morphology and spherical shape of nanoparticles. Magnetization measurements were measured by using Lake Shore 7304 model Vibrating Sample Magnetometer. In hemolytic activity tests, formation of a precipitate with a characteristic black color provided an explicit evidence to the formation of heme-iron complexes. Undesirable hemolytic effect of CoFe2O4 nanoparticles on human erythrocytes at both concentrations was attributed to the comparatively high amount of reactive oxygen species formed by CoFe2O4 nanoparticles. The theoretical concentration Co (theory) obtained by second-order model (0.82 mg/L) fit with the experimental value of Co (experimental) (0.95 mg/L) well in photocatalytic activity tests.

Facile Fabrication and Characterization of Ytterbium Oxide Hollow Spheres using Carbon Spheres as Template

NANO ◽  
2016 ◽  
Vol 11 (06) ◽  
pp. 1650067 ◽  
Author(s):  
Xueliang Jiang ◽  
Lu Yu ◽  
Chu Yao ◽  
Feng You ◽  
Jiao Zhang
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Hollow Spheres ◽  
Hollow Structure ◽  
Area Measurement ◽  
Precipitation Method ◽  
Synthesis Process ◽  
Carbon Spheres ◽  
Ytterbium Oxide ◽  
X Ray

Uniform rare-earth ytterbium oxide (Yb2O3) hollow microspheres have been successfully prepared via a urea-based homogenous precipitation method using carbon spheres as template, followed by a heat treatment. The main synthesis process was carried out in aqueous conditions without any organic solvents, surfactants or etching agents. X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetry, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller surface area measurement were employed to characterize the samples. The results show that the final products can be indexed to cubic Yb2O3 phase with high purity. The as-obtained Yb2O3 microspheres with spherical shape and hollow structure are uniform in size and distribution of about 450[Formula: see text]nm and wall thickness of approximately 15[Formula: see text]nm.

Tetraphenylbenzene-based AIEgens: the Horizontally Oriented Emitters for highly Efficient Non-doped Deep Blue OLEDs and Host for High-Performance Hybrid WOLEDs

2020 ◽  
Author(s):  
Pengbo Han ◽  
Zeng Xu ◽  
Chengwei Lin ◽  
Dongge Ma ◽  
Anjun Qin ◽  
...  
Keyword(s):  
High Performance ◽  
General Strategy ◽  
Flat Panel Displays ◽  
Light Emitting ◽  
Horizontal Orientation ◽  
Deep Blue ◽  
Full Color ◽  
High Emission ◽  
White Oleds ◽  
Low Efficiency

Deep blue organic-emitting fluorophores are crucial for application in white lighting and full color flat-panel displays but emitters with high color quality and efficiency are rare. Herein, novel deep blue AIE luminogens (AIEgens) with various donor units and an acceptor of cyano substituted tetraphenylbenzene (TPB) cores were developed and used to fabricate non-doped deep blue and hybrid white organic light-emitting diodes (OLEDs). Benefiting from its high emission efficiency and high proportion of horizontally oriented dipoles in the film state, the non-doped deep blue device based on CN-TPB-TPA realized a maximum external quantum efficiency 7.27%, with a low efficiency roll-off and CIE coordinates of (0.15, 0.08). Moreover, efficient two-color hybrid warm white OLEDs (CIE<sub>x,y</sub> = 0.43, 0.45) were achieved using CN-TPB-TPA as the blue-emitting layer and phosphor doped host, which realized maximum current, power, external quantum efficiencies 58.0 cd A<sup>-1</sup>, 60.7 lm W<sup>-1</sup> and 19.1%, respectively. This work provides a general strategy to achieve high performance, stable deep blue and hybrid white OLEDs by construction of AIEgens with excellent horizontal orientation

Efficient organic manganese (II) bromide green-light-emitting diodes enabled by manipulating hole and electron transport layer

2021 ◽  
Author(s):  
Hyunsik Im ◽  
Atanu Jana ◽  
Vijaya Gopalan Sree ◽  
QIANKAI BA ◽  
Seong Chan Cho ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Green Light ◽  
Transport Layer ◽  
Lead Free ◽  
Electron Transport Layer ◽  
Flat Panel Displays ◽  
Flat Panel ◽  
Inorganic Hybrid ◽  
Light Emitting ◽  
Light Emitting Devices

Lead-free, non-toxic transition metal-based phosphorescent organic–inorganic hybrid (OIH) compounds are promising for next-generation flat-panel displays and solid-state light-emitting devices. In the present study, we fabricate highly efficient phosphorescent green-light-emitting diodes...

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