Synthesis and characterization of mesoporous silica core-shell particles

Core-shell particles were formed by deposition of primary silica particles synthesized from sodium silicate solution on functionalized silica core particles (having size of ~0.5 ?m) prepared by hydrolysis and condensation of tetraethylortosilicate. The obtained mesoporous shell has thickness of about 60 nm and consists of primary silica particles with average size of ~21 nm. Scanning electron microscopy and zeta potential measurements showed that continuous silica shell exists around functionalized core particles which was additionally proved by FTIR and TEM results.

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Effect of reaction time on formation of silica core/shell particles

Processing and Application of Ceramics ◽

10.2298/pac1504209n ◽

2015 ◽

Vol 9 (4) ◽

pp. 209-214 ◽

Cited By ~ 2

Author(s):

Milan Nikolic ◽

Radoslav Filipovic ◽

Slobodanka Stanojevic-Nikolic

Keyword(s):

Reaction Time ◽

Mesoporous Silica ◽

Silica Nanoparticles ◽

Sodium Silicate ◽

Sodium Silicate Solution ◽

Silicate Solution ◽

Core Shell ◽

Silica Core ◽

Shell Particles ◽

Core Particles

The silica core/shell nanostructures were prepared by a wet-chemical process. Silica core particles were prepared by hydrolysis and condensation of tetraethylorthosilicate. The obtained particles (average size ~0.4 ?m) were used as templates for assembling of silica nanoparticles generated from highly basic sodium silicate solution. The silica core particles were functionalized with 3-aminopropyltriethoxysilane (APTES) to allow electrostatic assembling of silica nanoparticles on the surface of silica core particles. In order to find the optimal conditions for synthesis of silica core/shell particles with mesoporous shells, the effect of reaction time on formation of silica nanoparticles was investigated. The effect of process parameters on generation and aggregation of silica nanoparticles prepared from highly basic sodium silicate solution was also investigated. It was shown that the size of silica nanoparticles and tendency towards aggregation increase with increasing the reaction time and temperature. These behaviours were reflected on the formation of mesoporous silica shell around silica core particles. Thin and uniform mesoporous silica layers were obtained if reaction times were kept short. When the reaction time was prolonged, the thicker and non-uniform shells were obtained.

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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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Charge-based characterization of nanometric cationic bifunctional maghemite/silica core/shell particles by capillary zone electrophoresis

Electrophoresis ◽

10.1002/elps.200800835 ◽

2009 ◽

Vol 30 (14) ◽

pp. 2572-2582 ◽

Cited By ~ 39

Author(s):

Fanny d'Orlyé ◽

Anne Varenne ◽

Thomas Georgelin ◽

Jean-Michel Siaugue ◽

Bruno Teste ◽

...

Keyword(s):

Capillary Zone Electrophoresis ◽

Core Shell ◽

Zone Electrophoresis ◽

Capillary Zone ◽

Silica Core ◽

Shell Particles

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Preparation and Characterization of Gold-Loaded Magnetite/Silica Core-Shell Composites

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.42.47 ◽

2016 ◽

Vol 42 ◽

pp. 47-52

Author(s):

Dan Dan Huang ◽

Zhao Dai ◽

Kun Yang ◽

Yuan Yuan Chu

Keyword(s):

Room Temperature ◽

Solvothermal Reaction ◽

Core Shell ◽

X Ray Diffraction ◽

X Ray ◽

The Core ◽

Transmission Electron ◽

Silica Core ◽

Shell Particles

The fabrication of gold-loaded magnetite/silica core-shell particles was presented in this paper. First, 250 nm of magnetic Fe3O4 nanoparticles were prepared by solvothermal reaction. Then, the Fe3O4 particles were coated by SiO2, and Au nanoparticles (AuNPs), respectively. The core-shell structure of these microspheres was confirmed by transmission electron microscopy (TEM) and Power X-ray diffraction (XRD). The magnetic property of the core-shell microspheres was investigated at room temperature. The results indicated that the core-shell composites had a well-retained high magnetic intensity, thus it can be easily separated from the mixture in less than a few minutes by simply using a magnet.

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Toughening of epoxy resin with poly(methyl methacrylate) grafted silica core-shell particles

e-Polymers ◽

10.1515/epoly.2011.11.1.710 ◽

2011 ◽

Vol 11 (1) ◽

Cited By ~ 1

Author(s):

Peng Yang ◽

Liyuan Zhu ◽

Haitao Wang ◽

Qiangguo Du ◽

Wei Zhong

Keyword(s):

Methyl Methacrylate ◽

Epoxy Resin ◽

Thermo Gravimetric Analysis ◽

Silica Particles ◽

Core Shell ◽

Gravimetric Analysis ◽

Significant Deterioration ◽

Poly Methyl Methacrylate ◽

Silica Core ◽

Shell Particles

AbstractStructurally well-defined core-shell particles were prepared by modifying the surface of silica with initiators for atom transfer radical polymerization (ATRP), and followed by using these initiator-modified particles as ATRP macro-initiators for methyl methacrylate. These particles were characterized with Fourier-transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA) and scanning electron microscopy (SEM). The tethered polymer chains on the grafted silica particles were cleaved with hydrofluoric acid and measured with gel permeation chromatography (GPC). The results showed that poly(methyl methacrylate) (PMMA) chains grew from the particle surfaces in form of individual particles comprising of a hard silica core and a well-defined, densely grafted outer polymer layer. Diglycidyl ether of bisphenol-A (DGEBA) based epoxy resin was toughened with various doses of the synthesized PMMA-grafted silica particles. Resulting composite materials were characterized by tensile testing, SEM, dynamic mechanical analysis (DMA) and TGA. The results indicated that the incorporation of the core-shell particles improved the toughness of the composites without any significant deterioration of its thermal properties.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.997.317 ◽

2014 ◽

Vol 997 ◽

pp. 317-320 ◽

Cited By ~ 2

Author(s):

Huan Wang ◽

Ya Bing Liu ◽

Ling Wei Kong

Keyword(s):

Smooth Surface ◽

Annealing Temperature ◽

Sol Gel ◽

Spherical Shape ◽

Core Shell ◽

The Core ◽

Sol Gel Process ◽

Shell Particles ◽

Average Size

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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One-pot synthesis of micron partly hollow anisotropic dumbbell shaped silica core–shell particles

Chemical Communications ◽

10.1039/c6cc07372g ◽

2016 ◽

Vol 52 (100) ◽

pp. 14392-14395 ◽

Cited By ~ 1

Author(s):

Johannes Maisch ◽

Farhad Jafarli ◽

Thomas Chassé ◽

Felix Blendinger ◽

Alexander Konrad ◽

...

Keyword(s):

Silica Particles ◽

Core Shell ◽

One Pot ◽

One Pot Synthesis ◽

Spherical Silica ◽

Spherical Silica Particles ◽

One Step ◽

Silica Core ◽

Shell Particles

Anisotropic dumbbell silica core–shell particles are prepared from nonporous spherical silica particles in one step. The smaller lobe of the particles is hollow and can be loaded with molecules.

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