scholarly journals Synthesis and photoluminescence properties of silica-modified SiO 2 @ANA-Si-Tb@SiO 2 , SiO 2 @ANA-Si-Tb-L@SiO 2 core–shell–shell nanostructured composites

2019 ◽  
Vol 6 (8) ◽  
pp. 190182
Author(s):  
Lina Feng ◽  
Wenxian Li ◽  
Jinrong Bao ◽  
Yushan Zheng ◽  
Yilian Li ◽  
...  
Keyword(s):  
Surface Active Agent ◽  
Active Agent ◽  
Organic Ligand ◽  
Ammonium Bromide ◽  
Core Shell ◽  
Organic Complex ◽  
Chemical Route ◽  
Covalent Bonds ◽  
Nanostructured Composites ◽  
The Core

Three novel core–shell nanostructured composites SiO 2 @ANA-Si-Tb, SiO 2 @ANA-Si-Tb-L (L = second ligand) with SiO 2 as the core and terbium organic complex as the shell were successfully synthesized. The core and shell were connected together by covalent bonds. The terbium ion was coordinated with organic ligand-forming terbium organic complex in the shell layer. The organosilane (HOOCC 5 H 4 NN(CONH(CH 2 ) 3 Si(OCH 2 CH 3 ) 3 ) 2 (abbreviated as ANA-Si) was used as the first ligand and 1,10-phenanthroline (phen) or 2-thenoyltrifluoroacetone (TTA) was used as the second ligand. Furthermore, silica-modified SiO 2 @ANA-Si-Tb@SiO 2 , SiO 2 @ANA-Si-Tb-L@SiO 2 core–shell–shell nanostructured composites were also synthesized by sol–gel chemical route, which involved the hydrolysis and polycondensation processes of tetraethoxysilane (TEOS) using cetyltrimethyl ammonium bromide (CTAB) as a surface-active agent. An amorphous silica shell was coated around the SiO 2 @ANA-Si-Tb, SiO 2 @ANA-Si-Tb-L core–shell nanostructured composites. The core–shell and core–shell–shell nanostructured composites exhibited excellent luminescence in the solid state. Meanwhile, an improved luminescent stability property of the core–shell–shell nanostructured composites was observed for the aqueous solution. This type of core–shell–shell nanostructured composites exhibited bright luminescence, high stability and good solubility, which may present potential applications in the fields of optoelectronic devices, bio-imaging, medical diagnosis and study on the structure of function composite materials.

scholarly journals Synthesis and Luminescence Properties of Core-Shell-Shell Composites: SiO2@PMDA-Si-Tb@SiO2 and SiO2@PMDA-Si-Tb-phen@SiO2

2019 ◽  
Author(s):  
Lina Feng ◽  
Wenxian Li ◽  
Jinrong Bao ◽  
Yushang Zheng ◽  
Yilian Li ◽  
...  
Keyword(s):  
Organic Ligand ◽  
Silica Shell ◽  
Core Shell ◽  
Organic Complex ◽  
Chemical Route ◽  
The Core ◽  
Good Solubility ◽  
Potential Applications ◽  
Long Lifetime ◽  
Terbium Ion

Two novel core-shell composites SiO2@PMDA-Si-Tb, SiO2@PMDA-Si-Tb-phen with SiO2 as the core and terbium organic complex as the shell, were successfully synthesized. The terbium ion was coordinated with organic ligand forming terbium organic complex in the shell layer. The bi-functional organosilane ((HOOC)2C6H2(CONH(CH2)3Si(OCH2CH3)3)2 (abbreviated as PMDA-Si) was used as the first ligand and phen as the second ligand. Furthermore, the silica-modified SiO2@PMDA-Si-Tb@SiO2, SiO2@PMDA-Si-Tb-phen@SiO2 core-shell-shell composites were also synthesized by sol–gel chemical route. An amorphous silica shell was coated around the SiO2@PMDA-Si-Tb and SiO2@PMDA-Si-Tb-phen core-shell composites. The core-shell and core-shell-shell composites both exhibited excellent luminescence in solid state. The luminescence of core-shell-shell composites was stronger than that of core-shell composites. Meanwhile, an improved luminescence stability property for the core-shell-shell composites was found in the aqueous solution. The core-shell-shell composites exhibited bright luminescence, high stability, long lifetime, and good solubility, which may present potential applications in the field of bio-medical.

scholarly journals Synthesis and Luminescence Properties of Core-Shell-Shell Composites: SiO2@PMDA-Si-Tb@SiO2 and SiO2@PMDA-Si-Tb-phen@SiO2

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 189 ◽  
Author(s):  
Lina Feng ◽  
Wenxian Li ◽  
Jinrong Bao ◽  
Yushan Zheng ◽  
Yilian Li ◽  
...  
Keyword(s):  
Sol Gel ◽  
Organic Ligand ◽  
Core Shell ◽  
Organic Complex ◽  
Chemical Route ◽  
The Core ◽  
Good Solubility ◽  
Potential Applications ◽  
Long Lifetime ◽  
Terbium Ion

Two novel core-shell composites SiO2@PMDA-Si-Tb, SiO2@PMDA-Si-Tb-phen with SiO2 as the core and terbium organic complex as the shell, were successfully synthesized. The terbium ion was coordinated with organic ligand forming terbium organic complex in the shell layer. The bi-functional organosilane ((HOOC)2C6H2(CONH(CH2)3Si(OCH2CH3)3)2 (abbreviated as PMDA-Si) was used as the first ligand and phen as the second ligand. Furthermore, the silica-modified SiO2@PMDA-Si-Tb@SiO2 and SiO2@PMDA-Si-Tb-phen@SiO2 core-shell-shell composites were also synthesized by sol-gel chemical route. An amorphous silica shell was coated around the SiO2@PMDA-Si-Tb and SiO2@PMDA-Si-Tb-phen core-shell composites. The core-shell and core-shell-shell composites both exhibited excellent luminescence in solid state. The luminescence of core-shell-shell composites was stronger than that of core-shell composites. Meanwhile, an improved luminescence stability property for the core-shell-shell composites was found in the aqueous solution. The core-shell-shell composites exhibited bright luminescence, high stability, long lifetime, and good solubility, which may present potential applications in the bio-medical field.

Synthesis and Optical Properties of CdSe and CdSe/ZnS Core/Shell Quantum Dots

2015 ◽  
Vol 1085 ◽  
pp. 176-181
Author(s):  
Puspendu Barik ◽  
Arup Ratan Mandal ◽  
Denis V. Kuznetsov ◽  
Anna Yu. Godymchuk
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Excitation Wavelength ◽  
Core Shell ◽  
Shell Material ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
X Ray ◽  
The Core ◽  
Transmission Electron

In this work, we have synthesized homogeneous, ordered CdSe and CdSe/ZnS core/shell quantum dots (QDs) by chemical route and characterized them using X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and Photoluminescence (PL) spectroscopy. Coating with shell material was confirmed by red shift as well as enhancement in the PL peak compared to bare QDs. DLS data showed QDs and core/shell to be stable. PL spectra are red shifted relative to the excitation wavelength. Bare QDs and the core/shell material shows a Stoke-shift of 16 and 18 meV respectively.

Preparation and characterization of ZnS nanoparticles prepared by hydrothermal method

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744055 ◽  
Author(s):  
Caifeng Wang ◽  
Qingshan Li ◽  
Bo Hu
Keyword(s):  
Energy Level ◽  
Hydrothermal Method ◽  
Growth Temperature ◽  
Surface Active Agent ◽  
Active Agent ◽  
Green Emission ◽  
Zinc Nitrate ◽  
Ammonium Bromide ◽  
Zns Nanoparticles ◽  
Green Emission Band

ZnS nanoparticles were prepared by hydrothermal method using zinc nitrate [Zn(NO[Formula: see text] ⋅ 6H2O] and thiourea [SC(NH[Formula: see text]] as sources of Zn[Formula: see text] and S[Formula: see text] ions and cetyltrimethyl ammonium bromide [CH3(CH2)[Formula: see text]N[Formula: see text](CH3)3 ⋅ Br[Formula: see text]; CTAB] as a surface active agent. The structural, surface morphology and optical properties of ZnS nanoparticles as a function of growth temperature were investigated. The studies show that ZnS nanoparticles have high transmittance over 70% in the visible light range of 400–800 nm, and it has a strong green emission band at about 520 nm which originates from the recombination of electrons from the energy level of sulfur vacancies with the holes from the energy level of zinc vacancies. With the increase of the growth temperature, the XRD peak intensity and the size of ZnS nanoparticles increase, while the green emission intensity firstly increases and then decreases.

Magnetic Properties of Fe3O4/CoFe2O4 Composite Nanoparticles with Core/Shell Architecture

2020 ◽  
Vol 65 (10) ◽  
pp. 904
Author(s):  
V. O. Zamorskyi ◽  
Ya. M. Lytvynenko ◽  
A. M. Pogorily ◽  
A. I. Tovstolytkin ◽  
S. O. Solopan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Spinel Ferrite ◽  
Composite Nanoparticles ◽  
Core Shell ◽  
Cofe2o4 Nanoparticles ◽  
Core Diameter ◽  
The Core ◽  
Shell Particles ◽  
Interface Parameters ◽  
Shell Composite

Magnetic properties of the sets of Fe3O4(core)/CoFe2O4(shell) composite nanoparticles with a core diameter of about 6.3 nm and various shell thicknesses (0, 1.0, and 2.5 nm), as well as the mixtures of Fe3O4 and CoFe2O4 nanoparticles taken in the ratios corresponding to the core/shell material contents in the former case, have been studied. The results of magnetic research showed that the coating of magnetic nanoparticles with a shell gives rise to the appearance of two simultaneous effects: the modification of the core/shell interface parameters and the parameter change in both the nanoparticle’s core and shell themselves. As a result, the core/shell particles acquire new characteristics that are inherent neither to Fe3O4 nor to CoFe2O4. The obtained results open the way to the optimization and adaptation of the parameters of the core/shell spinel-ferrite-based nanoparticles for their application in various technological and biomedical domains.

Adjunctive Use of a Surface-Active Agent in Extracorporeal Circulation

Circulation ◽  
1966 ◽  
Vol 33 (4s1) ◽  
Author(s):  
YOSHIMASA MIYAUCHI ◽  
TAKAYUKI INOUE ◽  
BRUCE C. PATON
Keyword(s):  
Extracorporeal Circulation ◽  
Surface Active Agent ◽  
Active Agent ◽  
Surface Active

scholarly journals Iron Based Core-Shell Structures as Versatile Materials: Magnetic Support and Solid Catalyst

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 72
Author(s):  
Christian Zambrzycki ◽  
Runbang Shao ◽  
Archismita Misra ◽  
Carsten Streb ◽  
Ulrich Herr ◽  
...  
Keyword(s):  
Water Purification ◽  
Functional Materials ◽  
Core Material ◽  
Solid Catalyst ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
The Core ◽  
Shell Nanostructures ◽  
Sio2 Shell ◽  
Iron Based

Core-shell materials are promising functional materials for fundamental research and industrial application, as their properties can be adapted for specific applications. In particular, particles featuring iron or iron oxide as core material are relevant since they combine magnetic and catalytic properties. The addition of an SiO2 shell around the core particles introduces additional design aspects, such as a pore structure and surface functionalization. Herein, we describe the synthesis and application of iron-based core-shell nanoparticles for two different fields of research that is heterogeneous catalysis and water purification. The iron-based core shell materials were characterized by transmission electron microscopy, as well as N2-physisorption, X-ray diffraction, and vibrating-sample magnetometer measurements in order to correlate their properties with the performance in the target applications. Investigations of these materials in CO2 hydrogenation and water purification show their versatility and applicability in different fields of research and application, after suitable individual functionalization of the core-shell precursor. For design and application of magnetically separable particles, the SiO2 shell is surface-functionalized with an ionic liquid in order to bind water pollutants selectively. The core requires no functionalization, as it provides suitable magnetic properties in the as-made state. For catalytic application in synthesis gas reactions, the SiO2-stabilized core nanoparticles are reductively functionalized to provide the catalytically active metallic iron sites. Therefore, Fe@SiO2 core-shell nanostructures are shown to provide platform materials for various fields of application, after a specific functionalization.

scholarly journals Light-Scattering Simulations from Spherical Bimetallic Core–Shell Nanoparticles

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 359
Author(s):  
Francesco Ruffino
Keyword(s):  
Optical Properties ◽  
Light Scattering ◽  
Bimetallic Nanoparticles ◽  
Dominant Role ◽  
Scattered Light ◽  
Specific Interaction ◽  
Surface Enhanced Raman Spectroscopy ◽  
Localized Surface Plasmon ◽  
Core Shell ◽  
The Core

Bimetallic nanoparticles show novel electronic, optical, catalytic or photocatalytic properties different from those of monometallic nanoparticles and arising from the combination of the properties related to the presence of two individual metals but also from the synergy between the two metals. In this regard, bimetallic nanoparticles find applications in several technological areas ranging from energy production and storage to sensing. Often, these applications are based on optical properties of the bimetallic nanoparticles, for example, in plasmonic solar cells or in surface-enhanced Raman spectroscopy-based sensors. Hence, in these applications, the specific interaction between the bimetallic nanoparticles and the electromagnetic radiation plays the dominant role: properties as localized surface plasmon resonances and light-scattering efficiency are determined by the structure and shape of the bimetallic nanoparticles. In particular, for example, concerning core-shell bimetallic nanoparticles, the optical properties are strongly affected by the core/shell sizes ratio. On the basis of these considerations, in the present work, the Mie theory is used to analyze the light-scattering properties of bimetallic core–shell spherical nanoparticles (Au/Ag, AuPd, AuPt, CuAg, PdPt). By changing the core and shell sizes, calculations of the intensity of scattered light from these nanoparticles are reported in polar diagrams, and a comparison between the resulting scattering efficiencies is carried out so as to set a general framework useful to design light-scattering-based devices for desired applications.

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