Synthesis and Characterization of Monodisperse Spherical SiO2@Y2O3: Tb3+ Particles with Core-Shell Structure

Spherical submicron SiO2 particles have been coated with luminescent Y2O3: Tb3+ layers by a Pechini sol-gel process, resulting in the formation of SiO2@Y2O3: Tb3+ core-shell particles. The obtained core–shell phosphors have perfect spherical shape with narrow size distribution (average size ca. 450 nm), smooth surface and non-agglomeration. The thickness of shells could be easily controlled by changing the number of deposition cycles (35 nm for two deposition cycles). Under the excitation of ultraviolet, the Tb3+ ion mainly shows its characteristic emissions in the core-shell particles from Y2O3: Tb3+) shells. The emission intensity of Tb3+ can be tuned by the annealing temperature and the number of coating cycles.

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Synthesis and Photoluminescence Properties of Monodisperse Spherical SiO2@Lu2O3: Eu3+ Particles with Core-Shell Structure

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1004-1005.389 ◽

2014 ◽

Vol 1004-1005 ◽

pp. 389-392

Author(s):

Huan Wang

Keyword(s):

Smooth Surface ◽

Sol Gel ◽

Spherical Shape ◽

Core Shell ◽

Narrow Size Distribution ◽

Photoluminescence Properties ◽

The Core ◽

Sol Gel Process ◽

Core Shell Structure ◽

Shell Particles

Spherical submicron SiO2 particles have been coated with luminescent Lu2O3: Eu3+ layers by a Pechini sol-gel process, resulting in the formation of SiO2@Lu2O3: Eu3+ core-shell particles(300, 500 nm). The obtained core–shell phosphors have perfect spherical shape with narrow size distribution, smooth surface and non-agglomeration. The thickness of shells could be easily controlled by changing the number of deposition cycles (50 nm for four deposition cycles). Under the excitation of ultraviolet, the Eu3+ ion mainly shows its characteristic emissions in the core-shell particles from Lu2O3: Eu3+) shells. The PL intensity of Eu3+ increases with the number of coating cycles.

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Synthesis and Characterization of SiO2@Y2MoO6:Eu3+ Core–Shell Structured Spherical Phosphors by Sol–Gel Process

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2016.11862 ◽

2016 ◽

Vol 16 (4) ◽

pp. 3914-3920 ◽

Cited By ~ 1

Author(s):

G. Z Li ◽

F. H Liu ◽

Z. S Chu ◽

D. M Wu ◽

L. B Yang ◽

...

Keyword(s):

Electron Microscopy ◽

Annealing Temperature ◽

Uv Light ◽

Sol Gel ◽

Spherical Shape ◽

Core Shell ◽

X Ray ◽

Transmission Electron ◽

Sol Gel Process ◽

Average Size

SiO2@Y2MoO6:Eu3+ core–shell phosphors were prepared by the sol–gel process. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectra (EDS), transmission electron microscopy (TEM), photoluminescence (PL) spectra as well as kinetic decays were used to characterize the resulting SiO2@Y2MoO6:Eu3+ core–shell phosphors. The XRD results demonstrated that the Y2MoO6:Eu3+ layers on the SiO2 spheres crystallized after being annealed at 700 °C and the crystallinity increased with raising the annealing temperature. The obtained core–shell phosphors have spherical shape with narrow size distribution (average size ca. 640 nm), non-agglomeration, and smooth surface. The thickness of the Y2MoO6:Eu3+ shells on the SiO2 cores could be easily tailored by varying the number of deposition cycles (70 nm for four deposition cycles). The Eu3+ shows a strong PL emission (dominated by 5D0–7F2 red emission at 614 nm) under the excitation of 347 nm UV light. The PL intensity of Eu3+ increases with increasing the annealing temperature and the number of coating cycles.

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Synthesis and Luminescent Properties of Monodisperse Spherical SiO2/Ca10(PO4)6(OH)2: Eu3+ Particles with Core-Shell Structure

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1004-1005.344 ◽

2014 ◽

Vol 1004-1005 ◽

pp. 344-347

Author(s):

Huan Wang

Keyword(s):

Smooth Surface ◽

Calcium Phosphates ◽

Sol Gel ◽

Spherical Shape ◽

Luminescent Properties ◽

Core Shell ◽

X Ray Diffraction ◽

X Ray ◽

Sol Gel Process ◽

Shell Particles

The growing necessity of biomaterials has increased the interest in calcium phosphates, particularly hydroxyapatite. In this paper, monodisperse and spherical SiO2particles have been coated with Ca10(PO4)6(OH)2:Eu3+layers via a Pechini sol-gel process, resulting in core-chell ctructured SiO2/Ca10(PO4)6(OH)2:Eu3+samples. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), photoluminescence (PL) spectra were employed to characterize the SiO2/Ca10(PO4)6(OH)2:Eu3+core-shell particles. The resulted core-shell particles have perfect spherical shape with narrow size distribution, smooth surface and non-agglomeration.

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Influence of Various Reaction Parameters on the Process for Preparation of SiO2/TiO2 Core-Shell Particles

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.33.27 ◽

2015 ◽

Vol 33 ◽

pp. 27-37 ◽

Cited By ~ 1

Author(s):

Jhin Hong You ◽

Yi Yin Kuo ◽

Keh Ying Hsu

Keyword(s):

Inorganic Compounds ◽

Sol Gel ◽

Chelating Agent ◽

Condensation Process ◽

Infrared Analysis ◽

Ionic Surfactant ◽

Core Shell ◽

Reaction Parameters ◽

The Core ◽

Shell Particles

This study aims to describe the preparation and characterization of SiO2/TiO2 core-shell particles. In order to prepare the homogenous SiO2/TiO2 inorganic compounds by sol-gel process, SiO2 particles were used as the core, AcAc served as a chelating agent to chelate with TTIP (which was used as the precursor to TiO2), and PEG was added to stabilize the hydrolysis/condensation process. In addition, the ionic surfactant (SDS) and the nonionic surfactant (PVP) dispersed the core-shell particles. In order to improve the crystal structure, a high temperature was used to calcine the core-shell particles. The influence of various reaction parameters on the size, morphology and composition of the particles was also investigated. The properties of the particles were analyzed by electron microscopy, fourier transform infrared analysis, thermogravimetric analysis and powder X-ray diffraction.

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Sol-gel Synthesis and Characterization of Zn[sub 2]SiO[sub 4]:Mn@SiO[sub 2] Spherical Core-Shell Particles

Journal of The Electrochemical Society ◽

10.1149/1.1990612 ◽

2005 ◽

Vol 152 (9) ◽

pp. H146 ◽

Cited By ~ 53

Author(s):

D. Y. Kong ◽

M. Yu ◽

C. K. Lin ◽

X. M. Liu ◽

J. Lin ◽

...

Keyword(s):

Sol Gel ◽

Synthesis And Characterization ◽

Core Shell ◽

Spherical Core ◽

Shell Particles ◽

Sol Gel Synthesis

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Sol-gel derived Ba(Mg1/3Ta2/3)O3 thin films: Preparation and structure

Journal of Materials Research ◽

10.1557/jmr.1997.0087 ◽

1997 ◽

Vol 12 (3) ◽

pp. 596-599 ◽

Cited By ~ 6

Author(s):

Ji Zhou ◽

Qing-Xin Su ◽

K. M. Moulding ◽

D. J. Barber

Keyword(s):

Thin Films ◽

Annealing Temperature ◽

Volume Fraction ◽

Sol Gel ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Sol Gel Process ◽

Small Grains

Ba(Mg1/3Ta2/3)O3 thin films were prepared by a sol-gel process involving the reaction of barium isopropoxide, tantalum ethoxide, and magnesium acetate in 2-methoxyethanol and subsequently hydrolysis, spin-coating, and heat treatment. Transmission electron microscopy, x-ray diffraction, and Raman spectroscopy were used for the characterization of the thin films. It was shown that the thin films tend to crystallize with small grains sized below 100 nm. Crystalline phase with cubic (disordered) perovskite structure was formed in the samples annealed at a very low temperature (below 500 °C), and well-crystallized thin films were obtained at 700 °C. Although disordered perovskite is dominant in the thin films annealed below 1000 °C, a low volume fraction of 1 : 2 ordering domains was found in the samples and grows with an increase of annealing temperature.

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Synthesis and Characterization of Ag Nanoparticle, Ag-TiO2 Nanoparticle and Ag-TiO2-Chitosan Complex and Their Application to Antibiosis and Deodorization

MRS Proceedings ◽

10.1557/proc-820-o8.16 ◽

2004 ◽

Vol 820 ◽

Cited By ~ 2

Author(s):

Young Hwan Kim ◽

Young Soo Kang

Keyword(s):

Thermal Decomposition ◽

Sol Gel ◽

Oxide Shell ◽

Synthesis And Characterization ◽

Core Shell ◽

Ag Nanoparticle ◽

Sol Gel Process ◽

Core Shell Structure ◽

Silver Core

AbstractAg nanoparticles have been prepared by thermal decomposition of Ag-oleate complex using electric furnace at 300 °C for about 4 hrs. TEM images of the particles showed 2-dimensional assembly of particles with diameter of 8.0 ± 1.3 nm, demonstrating the uniformity of these nanoparticles. Ag-TiO2 nanoparticles were synthesized by sol-gel process and they had core-shell structure. Results showed the formation of the silver core and titanium oxide shell. In this study, we investigated the structure of Ag nanoparticle and Ag-TiO2 nanoparticle and Ag-TiO2-chitosan complex and their functions of antibiosis and deodorization.

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Structural and Spectroscopic Characterization of PM 597 Dye-Silica Core-Shell Nanoparticles

Journal of Spectroscopy ◽

10.1155/2015/901032 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7

Author(s):

Tahani R. Al-Biladi ◽

A. S. Al Dwayyan ◽

M. Naziruddin Khan ◽

Saif M. H. Qaid ◽

Khalid Al Zahrani

Keyword(s):

Emission Spectra ◽

Spectroscopic Characterization ◽

Core Shell ◽

Shell Nanoparticles ◽

Silica Core ◽

Shell Particles ◽

Average Size ◽

Core Shell Nanoparticles ◽

20 Nm

Nanostructured fluorescent pyrromethene (PM) doped-silica core-shell particles were successfully prepared by Stöber process. The average size of the particles was in the range of 10–20 nm measured by TEM micrograph. The atomic structure and morphology of PM 597/SiO2core/shell nanoparticles were studied by AFM and SEM, respectively. Absorption and emission spectra of the PM 597/SiO2core/shell nanoparticles under the UV irradiation were studied and not significantly influenced at the position of peaks. Finally, amplified spontaneous emission (ASE) and photobleaching of dye were examined and found no significant influence on the peaks of PM dye due to the formation of smaller sizes of PM 597/SiO2core/shell nanoparticles. The observed PM 597/SiO2core/shell nanoparticles were different in shapes with smaller size distribution and highly luminescent. Majority of nanoparticles were roughly spherical with many of them aggregated. The less photobleaching of dye core may be due to the protection of pumped energy by SiO2shell and restricts the leakage of dye.

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Effect of Calcination Temperature on the Morphology of Carbon Nanosphere Synthesized from Polymethylmethacrylate

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.974.55 ◽

2014 ◽

Vol 974 ◽

pp. 55-59 ◽

Cited By ~ 1

Author(s):

Abdullah F. Al-Ahmadi ◽

Mohammed A. Al-Daous ◽

Tawfik A. Saleh

Keyword(s):

Calcination Temperature ◽

Core Shell ◽

Carbon Nanospheres ◽

Batch Mode ◽

Resorcinol Formaldehyde ◽

X Ray ◽

The Core ◽

Shell Particles ◽

Hollow Carbon

In this work, hollow carbon nanospheres (HCNs) were synthesized by carbonizing core/shell particles of polymethylmethacrylate (PMMA)/ resorcinol formaldehyde. The core/shell particles were prepared using emulsion polymerization; polymethylmethacrylate as a template and resorcinol-formaldehyde polymer as the carbon source. Spheres were first synthesized by batch mode polymerization and then the shell was polymerized on the surface of the spheres. The composite was stabilized, and then carbonized. The effect of calcination temperature was investigated in the range between 200-500oC. Scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDX), Raman and Fourier transform infrared (FTIR) were used for characterization of the resulting carbon.

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