scholarly journals Synthesis, and Characteristic Luminescence of Core-Shell SiO2@Eu(MABA-Si)·(phen) Microspheres

2018 ◽  
Vol 142 ◽  
pp. 04002
Author(s):  
Yang-Yang Ma ◽  
Wen-Xian Li ◽  
Yu-Shan Zheng
Keyword(s):  
Silane Coupling Agent ◽  
Fluorescence Spectra ◽  
Silica Surface ◽  
Europium Complex ◽  
Molar Conductivity ◽  
Core Shell ◽  
Element Analysis ◽  
The Core ◽  
Silane Coupling ◽  
20 Nm

Monodispersed SiO2@Eu(MABA-Si)·(phen) core-shell microspheres were synthesized by silane coupling agent method. The core-shell microspheres was used the europium complex Eu(MABA-Si)·(phen)2·(ClO4)3·2H2O as shell and SiO2 as the inorganic core. The europium complex shell has grafted to silica surface through forming a Si-O-Si bond. The europium complex was synthesized by HOOCC6H4N- (CONH(CH2)3Si(OCH2CH3)3)2 (denoted as MABA-Si) and phen coordinated europium perchlorate. The europium complex has been characterized by element analysis, molar conductivity, 1HNMR and IR. The TEM and SEM showed that the diameter of SiO2 core was about 400 nm and the thickness of the europium complex shell was about 20 nm. Fluorescence spectra illustrated that the core-shell microspheres have stronger fluorescence intensity than the europium complex which was 1.87 times.

scholarly journals Luminescence Properties of SiO2@Eu(phen-Si) (sulphoxide) Core-Shell Nanometer Composite

2018 ◽  
Vol 142 ◽  
pp. 04003
Author(s):  
Yi-Lian Li ◽  
Wen-Xian Li ◽  
Yu-Shan Zheng
Keyword(s):  
Ir Spectra ◽  
Shell Structure ◽  
Europium Complex ◽  
Molar Conductivity ◽  
Core Shell ◽  
Silica Spheres ◽  
Element Analysis ◽  
The Core ◽  
Core Shell Structure ◽  
Different Thickness

A novel ternary europium complex Eu(Phen-Si)·(H2L)2·(ClO4)3·6H2O was prepared using (phen)-N-(CONH(CH2)3Si(OCH2CH3)3)2 (Phen-Si) as the first ligand and 2-carboxyphenyl carboxymethyl sulphoxide (H2L) as the second ligand. The corresponding different thickness core-shell structure SiO2@Eu(phen-Si)·L nano composites were synthesized, with silica spheres as core, ternary europium complex (Eu(Phen-Si)·(H2L)2·(ClO4)3) as shell. The ternary europium complex has been characterized by element analysis, molar conductivity, and IR spectra. The SiO2@Eu(phen-Si)·L core-shell structure composite was characterized by TEM and IR spectra. Core-shell structure composites exhibited stronger fluorescence properties than that of the ternary europium complex. The emission intensity of the two core-shell composites was 1.79, 3.99 times stronger than the ternary europium complex, respectively. The fluorescence lifetime of the core-shell structure composites were longer than the ternary europium complex.

scholarly journals Preparation and characterization of attapulgite microcapsules coated with acrylic polymer

Polimery ◽  
2021 ◽  
Vol 66 (2) ◽  
pp. 112-118
Author(s):  
Lining Song ◽  
Zhenxu Li ◽  
Lina Yang ◽  
Ning Wang ◽  
Jie Zhao ◽  
...  
Keyword(s):  
Particle Size ◽  
Acrylic Acid ◽  
Methyl Methacrylate ◽  
Flame Retardant ◽  
Coupling Agent ◽  
Silane Coupling Agent ◽  
Core Shell ◽  
Shell Material ◽  
Poly Methyl Methacrylate ◽  
Silane Coupling

The attapulgite core-shell microcapsule type flame retardant was prepared by in situ polymerization. Attapulgite (ATP) was used as a core material with poly(methyl methacrylate) (PMMA) and poly(methyl methacrylate-co-acrylic acid) [P(MMA-co-AA)] as shell materials. The attapulgite was modified by the silane coupling agent. The effects of different shell materials and modification methods on the structure and properties of attapulgite core-shell microcapsules were studied by scanning electron microscopy, particle size distribution, infrared analysis and thermogravimetric analysis. The results showed that the coating effect was best when the amount of silane coupling agent was 1% of the attapulgite mass. The particle size of the microcapsule prepared with PMMA as shell material was uniform and the coating efficiency was better. After the copolymerization of acrylic acid (AA) in MMA shell materials, the cladding efficiency was improved. At the same time, the thermal decomposition temperature of the microcapsule shell material was greatly reduced, which is beneficial to the performance of attapulgite flame retardant.

Dispersion and Behavior of Silane Coupling Agent to Surface Modification of n-Cu Particles

2010 ◽  
Vol 92 ◽  
pp. 73-78 ◽  
Author(s):  
Xiao Li Wang ◽  
Bo Zhang ◽  
Yang Zhao ◽  
Yi Xu ◽  
Bin Shi Xu
Keyword(s):  
Surface Modification ◽  
Coupling Agent ◽  
Silane Coupling Agent ◽  
Wear Test ◽  
Friction Material ◽  
Test Machine ◽  
Silane Coupling ◽  
Surface Modified ◽  
20 Nm ◽  
And Behavior

The prepared n-Cu particles with the particle size about 20 nm by KBH4 reduction method in aqueous solution was surface modified using silane coupling agent. The surface modification mechanics was researched. The tribological performances of n-Cu particles were tested by friction wear test machine. The results show that the modified n-Cu paritcles by silane coupling agent have high purity, good dispersion performances and wonderful surface activity. In friction process, the modified n-Cu particles can form a layer of organic-inorganic compound film with synergistic effect on worn surface, which improves the tribological performances of friction material.

scholarly journals Preparation, and Luminescence Properties of SiO2@Sm(MABA-Si)phen Core-Shell Structure Nanometer Composite

2018 ◽  
Vol 142 ◽  
pp. 04001
Author(s):  
Li-Na Feng ◽  
Wen-Xian Li ◽  
Jin-Rong Bao
Keyword(s):  
Ir Spectra ◽  
Shell Structure ◽  
Luminescence Properties ◽  
Core Shell ◽  
Silica Spheres ◽  
Chemical Formula ◽  
Element Analysis ◽  
The Core ◽  
Samarium Complex ◽  
Core Shell Structure

A novel ternary samarium complex was prepared using HOOCC6H4N(CONH(CH2)3Si- (OCH2CH3)3)2 (MABA-Si) as first ligand, and phen as second ligand. The corresponding SiO2@Sm(MABA-Si)phen core-shell structure nanometer composite was synthesized as well, and the silica spheres was the core, and the ternary samarium complex was the shell layer. The ternary samarium complex has been characterized by element analysis, molar conductivity and IR spectra. The results show that the chemical formula of the complex is Sm(MABA-Si)(phen)2(ClO4)3·2H2O. The fluorescent spectra illustrat that the luminescence properties of the samarium complex are superior. The core-shell structure of SiO2@Sm(MABA-Si)phen nanometer composite is characterized by SEM, TEM and IR spectra. The SiO2@Sm(MABA-Si)phen core-shell structure composites exhibit stronger emission intensity than the ternary samarium complex. The fluorescence lifetime of the complex and core-shell structure composite is measured as well.

Synthesis and Characterization of Silica-LiMn2O4 Core-Shell Nanosphere Cathodes

2013 ◽  
Vol 1540 ◽  
Author(s):  
Jong-Moon Lee ◽  
Soon-Kie Hong ◽  
Won Il Cho ◽  
In-Hyeong Yeo ◽  
Sun-il Mho
Keyword(s):  
Silica Surface ◽  
Lithium Salt ◽  
Cycling Performance ◽  
Core Shell ◽  
Cycle Stability ◽  
Capacity Retention ◽  
The Core ◽  
Structurally Stable ◽  
Charge Discharge

ABSTRACTIn order to improve the charge/discharge cycling performance of the LiMn2O4 cathode, the spinel LiMn2O4 is coated on the structurally stable SiO2 nanosphere cores, LiMn2O4@SiO2. The core-shell LiMn2O4@SiO2 nanosphere cathodes are prepared by the MnCO3 precipitation on the silica surface and the following solid state reaction of MnCO3@SiO2 with a lithium salt. The charge/discharge cycle stability has improved by the nanostructural characteristics of the LiMn2O4@ shell on the SiO2 core. The cathode composed of LiMn2O4@SiO2 nanospheres exhibits higher capacity retention of 97% than that of LiMn2O4 nanoparticles of 89%, after 100 battery cycles at a 10C rate.

scholarly journals Preparation, characterization and luminescence properties of core–shell ternary terbium composites SiO 2(600) @Tb(MABA-Si)•L

2018 ◽  
Vol 5 (3) ◽  
pp. 171655 ◽  
Author(s):  
Yang-Yang Ma ◽  
Wen-Xian Li ◽  
Yu-Shan Zheng ◽  
Jin-Rong Bao ◽  
Yi-Lian Li ◽  
...  
Keyword(s):  
Shell Structure ◽  
Luminescence Decay ◽  
Luminescence Properties ◽  
Core Shell ◽  
Element Analysis ◽  
Strong Emission ◽  
The Core ◽  
Potential Applications ◽  
Core Shell Structure ◽  
Terbium Complexes

Two novel core–shell structure ternary terbium composites SiO 2(600) @Tb(MABA-Si)·L(L:dipy/phen) nanometre luminescence materials were prepared by ternary terbium complexes Tb(MABA-Si)·L 2 ·(ClO 4 ) 3 ·2H 2 O shell grafted onto the surface of SiO 2 microspheres. And corresponding ternary terbium complexes were synthesized using (CONH(CH 2 ) 3 Si(OCH 2 CH 3 ) 3 ) 2 (denoted as MABA-Si) as first ligand and L as second ligand coordinated with terbium perchlorate. The as-synthesized products were characterized by means of IR spectra, 1 HNMR, element analysis, molar conductivity, SEM and TEM. It was found that the first ligand MABA-Si of terbium ternary complex hydrolysed to generate the Si–OH and the Si–OH condensate with the Si–OH on the surface of SiO 2 microspheres; then ligand MABA-Si grafted onto the surface of SiO 2 microspheres. The diameter of SiO 2 core of SiO 2(600) @Tb(MABA-Si)·L was approximately 600 nm. Interestingly, the luminescence properties demonstrate that the two core–shell structure ternary terbium composites SiO 2(600) Tb(MABA-Si)·L(dipy/phen) exhibit strong emission intensities, which are 2.49 and 3.35 times higher than that of the corresponding complexes Tb(MABA-Si)·L 2 ·(ClO 4 ) 3 ·2H 2 O, respectively. Luminescence decay curves show that core–shell structure ternary terbium composites have longer lifetime. Excellent luminescence properties enable the core–shell materials to have potential applications in medicine, industry, luminescent fibres and various biomaterials fields.

REDUCED ETHANOL EMISSIONS BY A COMBINATION OF EPOXIDIZED NATURAL RUBBER AND SILANE COUPLING AGENT FOR SILICA-REINFORCED NATURAL RUBBER-BASED TIRE TREADS

2016 ◽  
Vol 89 (3) ◽  
pp. 419-435 ◽  
Author(s):  
K. Sengloyluan ◽  
K. Sahakaro ◽  
W. K. Dierkes ◽  
J. W. M. Noordermeer
Keyword(s):  
Organic Compound ◽  
Natural Rubber ◽  
Volatile Organic Compound ◽  
Coupling Agent ◽  
Silane Coupling Agent ◽  
Elemental Sulfur ◽  
Silica Surface ◽  
Epoxidized Natural Rubber ◽  
Volatile Organic ◽  
Silane Coupling

ABSTRACT In an attempt to reduce the high volatile organic compound (ethanol) emissions from silica-reinforced NR compounds, this work aimed to, at least partially, replace the use of large quantities of silane coupling agent bis-(3-triethoxysilylpropyl) tetrasulfide (TESPT). The use of 7.5 phr of epoxidized natural rubber (ENR-51) as compatibilizer between NR and silica enhances the properties, which can be further improved by half or even lower amounts than required with TESPT alone. The properties obtained with TESPT are nearly matched, except for steric limitations imposed upon the ENR molecules to cap the silanol groups on the silica surface to the same extent as TESPT can do. Furthermore, TESPT donates reactive elemental sulfur to the compound during vulcanization, which needs to be compensated for in use with ENR.

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