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.

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.

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.

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.

Electrochemical performance and electronic properties of shell LiNi0.5Mn1.5O4 hollow spheres for lithium ion battery

2016 ◽  
Vol 09 (02) ◽  
pp. 1650027 ◽  
Author(s):  
Yongli Cui ◽  
Jiali Wang ◽  
Mingzhen Wang ◽  
Quanchao Zhuang
Keyword(s):  
Activation Energy ◽  
Electrochemical Performance ◽  
Electronic Properties ◽  
Lithium Ion Battery ◽  
Retention Rate ◽  
Hollow Spheres ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Hollow Microspheres ◽  
Cycle Stability

Shell spinel LiNi[Formula: see text]Mn[Formula: see text]O4 hollow microspheres were successfully synthesized by MnCO3 template, and characterized by XRD, SEM, and TEM. The results show that the hollow LiNi[Formula: see text]Mn[Formula: see text]O4 cathode has good cycle stability to reach 124.5, 119.8, and 96.6[Formula: see text]mAh/g at 0.5, 1, and 5 C, the corresponding retention rate of 98.1%, 98.2%, and 98.0% after 50 cycles at 20[Formula: see text]C, and the reversible capacity of 94.6[Formula: see text]mAh/g can be obtained at 1 C rate at 55[Formula: see text]C, 83.3% retention after 100 cycles. As the temperature decreases from 10[Formula: see text]C to [Formula: see text]C, the resistance of [Formula: see text] increases from 5.5 [Formula: see text] to 135 [Formula: see text], [Formula: see text] from 27 [Formula: see text] to 353.2 [Formula: see text], and [Formula: see text] from 12.7 [Formula: see text] to 73.0 [Formula: see text]. Moreover, the B constant and [Formula: see text] activation energy are 4480[Formula: see text]K and 37.22[Formula: see text]KJ/mol for the NTC spinel material, respectively.

Hierarchical flower-like Bi2WO6 hollow microspheres: facile synthesis and excellent catalytic performance

RSC Advances ◽  
2015 ◽  
Vol 5 (29) ◽  
pp. 23080-23085 ◽  
Author(s):  
Peigen Zhang ◽  
Jian Zhang ◽  
Anjian Xie ◽  
Shikuo Li ◽  
Jiming Song ◽  
...  
Keyword(s):  
Hollow Spheres ◽  
Catalytic Performance ◽  
Hollow Microspheres ◽  
Solvothermal Process ◽  
Facile Synthesis ◽  
Step Method ◽  
Bismuth Tungstate ◽  
One Step ◽  
Excellent Catalytic Performance

A one step method has been developed for the fabrication of hierarchical flower-like bismuth tungstate (Bi2WO6) hollow spheres via a solvothermal process.

Superhydrophobic, highly adhesive arrays of copper hollow spheres produced by electro-colloidal lithography

Soft Matter ◽  
2017 ◽  
Vol 13 (33) ◽  
pp. 5500-5505 ◽  
Author(s):  
Damien Bazin ◽  
Chrystel Faure
Keyword(s):  
Chemical Modification ◽  
Electric Fields ◽  
Hollow Spheres ◽  
Hollow Microspheres ◽  
Colloidal Lithography ◽  
Adhesive Properties

Arrays of copper hollow microspheres produced under electric fields display anti-wetting and super-adhesive properties without resorting to any chemical modification.

A novel electrochemical immunoassay for carcinoembryonic antigen based on glucose oxidase-encapsulated nanogold hollow spheres with a pH meter readout

The Analyst ◽  
2018 ◽  
Vol 143 (21) ◽  
pp. 5271-5277 ◽  
Author(s):  
Yu Jiang ◽  
Zhiying Su ◽  
Jian Zhang ◽  
Meijiao Cai ◽  
Lili Wu
Keyword(s):  
Carcinoembryonic Antigen ◽  
Glucose Oxidase ◽  
Signal Amplification ◽  
Hollow Spheres ◽  
Electrochemical Immunosensor ◽  
Hollow Microspheres ◽  
Electrochemical Immunoassay

A portable electrochemical immunosensor was designed for the detection of CEA on a pH meter by using glucose oxidase-encapsulated gold hollow microspheres for signal amplification.

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.

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