Silica Coatings Pigmented with Core-Shell Particles for High-Temperature Radiation Heat Shields

2012 ◽  
Vol 512-515 ◽  
pp. 1074-1077
Author(s):  
Guang Hai Wang ◽  
Yue Zhang ◽  
Yu Feng Chen
Keyword(s):  
High Temperature ◽  
Volume Fraction ◽  
Sol Gel ◽  
Core Shell ◽  
Radiation Heat ◽  
Hollow Glass ◽  
Silica Coatings ◽  
Infrared Transmittance ◽  
Ft Ir ◽  
Shell Particles

Hollow glass micro-beads uniformly coated by a shell of titania with thickness of 50 to 300 nm, were fabricated by wet chemical methods. The pigments were dispersed in silica coatings，then the pigmented coatings were deposited on quartz substrates by sol-gel spin-coating method with a thickness of about 80 µm. SEM, TEM and FT-IR techniques were used to characterize the microstructure and properties of the coatings. FT-IR indicated average infrared transmittance of coatings containing the core-shell particles was significantly lower than that of coatings containing no functional particles or containing hollow glass micro-beads, when the volume fraction of core-shell particles was just 5%. In view of its low infrared transmittance, pigmented silica coatings may find applications in high-temperature heat-insulating materials for reducing radiation heat transfer.

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

2015 ◽  
Vol 33 ◽  
pp. 27-37 ◽  
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.

Preparation and Characterization of Core-Shell Latex Containing PDMS in the Shell

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Baotan Zhang ◽  
Bailing Liu ◽  
Shunsheng Cao ◽  
Xiaobo Deng
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hydrophobic Surface ◽  
Water Repellency ◽  
Atomic Ratio ◽  
Core Shell ◽  
Seeded Emulsion Polymerization ◽  
The Core ◽  
Static Contact ◽  
Ft Ir ◽  
Shell Particles

AbstractIn this paper, the composite latex particles with a polyacrylate (PA) core and a polydimethylsiloxane (PDMS) shell via 3-(methacryloxypropyl)- trimethoxy silane (MPS) as the medium to link the core and shell were prepared by semicontinuous seeded emulsion polymerization and were characterized by transmission electron microscopy (TEM), FT-IR, particle size analyzer and X-ray photoelectron spectroscopy (XPS). The TEM images indicated that the particles containing organic siloxane (D-40) displayed an evident core/shell structure. Additionally, the study by FT-IR and XPS also revealed that D4 could be grafted onto the surface of polyacrylate core because there appeared the characteristic peaks of Si-O-Si group and Si 2s and Si 2p in the spectra of FT-IR and XPS respectively. Besides, the atomic ratio of C/Si on the surface of the core/shell particles (D-40) was close to the ratio of C/Si in the latex of pure PDMS that could prove the PA particles were fully covered by PDMS and the properties of PDMS should be embodied in a maximal level. In order to testify the result, the surface properties of the films produced from the core/shell particles were also investigated by the static contact angle method. Compared with the copolymer of PA, the core/shell particles were more effective to create hydrophobic surface, so, the introduction of D4 was capable of obvious increase in water repellency.

Spherical SiO2 @ GdPO4 : Eu3+ Core–Shell Phosphors: Sol–Gel Synthesis and Characterization

2007 ◽  
Vol 7 (2) ◽  
pp. 542-548 ◽  
Author(s):  
Cuikun Lin ◽  
Bo Zhao ◽  
Zhenling Wang ◽  
Min Yu ◽  
Huan Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Low Voltage ◽  
Uv Light ◽  
Sol Gel ◽  
Emission Spectra ◽  
Core Shell ◽  
Time Resolved ◽  
Potential Applications ◽  
Ft Ir ◽  
Red Luminescence

Nanocrystalline GdPO4 : Eu3+ phosphor layers were coated on non-aggregated, monodisperse and spherical SiO2 particles by Pechini sol–gel method, resulting in the formation of core–shell structured SiO2 @ GdPO4 : Eu3+ particles. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), photoluminescence (PL), low-voltage cathodoluminescence (CL), time-resolved PL spectra and lifetimes were used to characterize the core–shell structured materials. Both XRD and FT-IR results indicate that GdPO4 layers have been successfully coated on the SiO2 particles, which can be further verified by the images of FESEM and TEM. Under UV light excitation, the SiO2 @ GdPO4 : Eu3+ phosphors show orange-red luminescence with Eu3+ 5D0–7F1 (593 nm) as the most prominent group. The PL excitation and emission spectra suggest that an energy transfer occurs from Gd3+ to Eu3+ in SiO2 @ GdPO4 : Eu3+ phosphors. The obtained core–shell phosphors have potential applications in FED and PDP devices.

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

2005 ◽  
Vol 152 (9) ◽  
pp. H146 ◽  
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

pH Affects Sol–Gel Formation of Core–Shell Mesoporous Silica Coatings on Polyamide

2013 ◽  
Vol 52 (2) ◽  
pp. 779-784 ◽  
Author(s):  
Junia N. M. Batista ◽  
Emerson H. de Faria ◽  
Paulo S. Calefi ◽  
Katia J. Ciuffi ◽  
Eduardo J. Nassar ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Sol Gel ◽  
Core Shell ◽  
Gel Formation ◽  
Silica Coatings

Spherical SiO2 @ GdPO4 : Eu3+ Core–Shell Phosphors: Sol–Gel Synthesis and Characterization

2007 ◽  
Vol 7 (2) ◽  
pp. 542-548
Author(s):  
Cuikun Lin ◽  
Bo Zhao ◽  
Zhenling Wang ◽  
Min Yu ◽  
Huan Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Low Voltage ◽  
Uv Light ◽  
Sol Gel ◽  
Emission Spectra ◽  
Core Shell ◽  
Time Resolved ◽  
Potential Applications ◽  
Ft Ir ◽  
Red Luminescence

Nanocrystalline GdPO4 : Eu3+ phosphor layers were coated on non-aggregated, monodisperse and spherical SiO2 particles by Pechini sol–gel method, resulting in the formation of core–shell structured SiO2 @ GdPO4 : Eu3+ particles. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), photoluminescence (PL), low-voltage cathodoluminescence (CL), time-resolved PL spectra and lifetimes were used to characterize the core–shell structured materials. Both XRD and FT-IR results indicate that GdPO4 layers have been successfully coated on the SiO2 particles, which can be further verified by the images of FESEM and TEM. Under UV light excitation, the SiO2 @ GdPO4 : Eu3+ phosphors show orange-red luminescence with Eu3+ 5D0–7F1 (593 nm) as the most prominent group. The PL excitation and emission spectra suggest that an energy transfer occurs from Gd3+ to Eu3+ in SiO2 @ GdPO4 : Eu3+ phosphors. The obtained core–shell phosphors have potential applications in FED and PDP devices.

Bifunctional Fe3O4@SiO2@Eu-Polyoxometalates Nanoparticles and Study on their Magnetism and Luminescence

2011 ◽  
Vol 284-286 ◽  
pp. 2224-2229 ◽  
Author(s):  
Hong Yan Zhang ◽  
Jun Wang ◽  
Shao Hua Fan
Keyword(s):  
Electron Microscopy ◽  
Luminescence Spectroscopy ◽  
Core Shell ◽  
Silica Spheres ◽  
Stöber Method ◽  
The Core ◽  
Transmission Electron ◽  
Ft Ir ◽  
Shell Particles ◽  
The Stöber Method

In this paper, we report the synthesis of the bifunctional Fe3O4@SiO2@Eu-polyoxometalates particles. The magnetite nanoparticles (Fe3O4) homogeneously coated with silica spheres prepared with the Stöber method. The so-obtained Fe3O4@SiO2 core/shell particles were modified by 3-aminopropyltriethoxysilane and finally grafted with the luminescent Europium -polyoxometalates. The core-shell particles were characterized by scanning electron microscopy, transmission electron microscopy, FT-IR, UV, magnetism and luminescence spectroscopy. The results indicated that the core-shell particles show both interesting luminescence and magnetic properties.

Design of SiO2/ZrO2 core–shell particles using the sol–gel process

2009 ◽  
Vol 35 (3) ◽  
pp. 1243-1247 ◽  
Author(s):  
Jong Min Kim ◽  
Sang Mok Chang ◽  
Sungkook Kim ◽  
Kyo-Seon Kim ◽  
Jinsoo Kim ◽  
...  
Keyword(s):  
Sol Gel ◽  
Core Shell ◽  
Sol Gel Process ◽  
Shell Particles
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