Synthesis and Photophysical Properties of Core–Shell Eu(DBM)3phen/TiO2 Nanohybrids

2008 ◽  
Vol 8 (3) ◽  
pp. 1464-1467 ◽  
Author(s):  
Weiping Qin ◽  
Dan Zhao ◽  
Jisen Zhang ◽  
Jishuang Zhang ◽  
Yan Wang ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Experimental Results ◽  
Core Shell ◽  
Complex Surfaces ◽  
Stöber Method ◽  
The Core ◽  
Ultraviolet Excitation ◽  
Modified Stöber Method ◽  
The Eu

The core–shell titania (TiO2) hybrid spheres embedded with tris(dibenzoylmethanato)phenanthroline [Eu-(DBM)3phen] complex clusters were fabricated by a modified Stöber method. Under ultraviolet excitation (355 nm), the hybrid spheres exhibit the characteristic luminescence of the Eu3+ ions. The experimental results indicate that the titanic shell has different influences on the two fluorescent centers of Eu3+ ions. The emission from the centers on the complex surfaces was greatly enhanced when incorporated into titania spheres.

Core–Shell Fe@SiO2 Nanoparticles Synthesized via Modified Stober Method for High Activity in Cr(VI) Reduction

2018 ◽  
Vol 18 (10) ◽  
pp. 6867-6872 ◽  
Author(s):  
Van Thi Thanh Ho ◽  
Nguyen Vu Hoa Hong ◽  
At Van Nguyen ◽  
Long Giang Bach ◽  
Tuan Phan Dinh
Keyword(s):  
High Activity ◽  
Sio2 Nanoparticles ◽  
Core Shell ◽  
Stöber Method ◽  
Modified Stöber Method

Responsive P(NIPAM-co-AA) Particle-Functionalized Magnetic Microspheres

2014 ◽  
Vol 67 (1) ◽  
pp. 134 ◽  
Author(s):  
Yiheng Wang ◽  
Mengge Xia ◽  
Yongtao Wu ◽  
Meifang Zhu
Keyword(s):  
Magnetic Microspheres ◽  
Core Shell ◽  
The Novel ◽  
Shell Nanoparticles ◽  
Stöber Method ◽  
Preparation Conditions ◽  
Amidation Reaction ◽  
Modified Stöber Method ◽  
Core Shell Nanoparticles ◽  
Seed Emulsion Polymerization

Functionalized magnetic microspheres were prepared by anchoring cross-linked core–shell poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAM-co-AA)) nanoparticles onto silica-coated magnetic microspheres (Fe3O4@SiO2). First, the smaller polystyrene/P(NIPAM-co-AA) core–shell nanoparticles were synthesized through seed emulsion polymerization and adhered to the surface of amino-modified Fe3O4@SiO2 micorspheres, which were made using the modified Stöber method through electrostatic interaction under appropriate preparation conditions. An amidation reaction between the carboxylic and amino groups on the respective surfaces was then catalyzed. Finally, the novel architecture magnetic microspheres with multiresponsive functionalities were obtained, and their polymerization conditions, environmental sensitivity, and magnetic properties were discussed and optimized. The superparamagnetism and temperature/pH dual responsivity and excellent dispersibility of the P(NIPAM-co-AA) functionalized magnetic microspheres provide them with high potential to be used in the fields of controlled drug delivery, bioseparation, and catalysis.

Preparation of structurally colored films assembled by using polystyrene@silica, air@silica and air@carbon@silica core–shell nanoparticles with enhanced color visibility

RSC Advances ◽  
2016 ◽  
Vol 6 (44) ◽  
pp. 37535-37543 ◽  
Author(s):  
Fen Wang ◽  
Xin Zhang ◽  
Jianfeng Zhu ◽  
Ying Lin
Keyword(s):  
Core Shell ◽  
Shell Nanoparticles ◽  
Stöber Method ◽  
Silica Core ◽  
Modified Stöber Method ◽  
Core Shell Nanoparticles

Polystyrene@silica (PS@SiO2) core–shell nanospheres were synthesized using a surfactant free method followed by a modified Stöber method in the research reported in this paper.

scholarly journals Simultaneous Adsorption and Degradation of Cr(VI) and Cd(II) Ions from Aqueous Solution by Silica-Coated Fe0Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yongchao Li ◽  
Hongpu Ma ◽  
Bozhi Ren ◽  
Tielong Li
Keyword(s):  
Aqueous Solution ◽  
Active Site ◽  
Removal Rate ◽  
Core Shell ◽  
Simultaneous Removal ◽  
Stöber Method ◽  
Removal Capacity ◽  
Batch Tests ◽  
One Step ◽  
Modified Stöber Method

Core-shell silica-coated Fe0nanoparticles (Fe@SiO2) were prepared in one-step synthesis by aqueous reduction combined with modified Stöber method. The as-prepared Fe@SiO2were then used for simultaneous removal of Cr(VI) and Cd(II) from aqueous solution. Batch tests indicated that Fe@SiO2exhibited high removal capacity toward Cr(VI) and Cd(II). Cr(VI) was removed by Fe@SiO2through reduction rather than adsorption, while Cd(II) removal was mainly through adsorption. The removal rate increased with increasing initial Fe NPs dose and decreased with increasing initial Cr(VI) and Cd(II) concentrations. Cd(II) adsorption was also strengthened by Cr(VI) reduction with the release of OH−. The removals of Cr(VI) and Cd(II) were weakened in the presence of cations or humic acid, as a result of aggregation and less active site of Fe@SiO2. Overall, the simply prepared Fe@SiO2were potential material for the heavy metals removed from water.

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.

scholarly journals Experimental Study on Expansion Characteristics of Core-Shell and Polymeric Microspheres

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Pengxiang Diwu ◽  
Baoyi Jiang ◽  
Jirui Hou ◽  
Zhenjiang You ◽  
Jia Wang ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Early Stage ◽  
Average Diameter ◽  
Control Agent ◽  
Field Application ◽  
Experimental Results ◽  
Core Shell ◽  
The Core ◽  
Profile Control ◽  
Polymeric Microsphere

Traditional polymeric microsphere has several technical advantages in enhancing oil recovery. Nevertheless, its performance in some field application is unsatisfactory due to limited blockage strength. Since the last decade, novel core-shell microsphere has been developed as the next-generation profile control agent. To understand the expansion characteristic differences between these two types of microspheres, we conduct size measurement experiments on the polymeric and core-shell microspheres, respectively. The experimental results show two main differences between them. First, the core-shell microsphere exhibits a unimodal distribution, compared to multimodal distribution of the polymeric microsphere. Second, the average diameter of the core-shell microsphere increases faster than that of the polymeric microsphere in the early stage of swelling, that is, 0–3 days. These two main differences both result from the electrostatic attraction between core-shell microspheres with different hydration degrees. Based on the experimental results, the core-shell microsphere is suitable for injection in the early stage to block the near-wellbore zone, and the polymeric microsphere is suitable for subsequent injection to block the formation away from the well. A simple mathematical model is proposed for size evolution of the polymeric and core-shell microspheres.

Nonsurfactant Surface Modifications of Monodispersed Si-Cu Core-Shell Nanocomposite

2014 ◽  
Vol 895 ◽  
pp. 571-574
Author(s):  
Musdalilah Ahmad Salim ◽  
Halina Misran ◽  
S.Z. Othman ◽  
N.N.H. Shah ◽  
N.A.A. Razak ◽  
...  
Keyword(s):  
Sol Gel ◽  
Core Shell ◽  
Silica Spheres ◽  
X Ray Diffraction ◽  
Stöber Method ◽  
X Ray ◽  
Silica Surfaces ◽  
Nonsurfactant Template ◽  
Diffraction Patterns ◽  
Modified Stöber Method

Monodispersed silica spheres with particles size of ca. 450 nm were successfully synthesized using modified Stöber method. The synthesized monodispersed silica spheres were successfully coated with copper through modified sol-gel method employing nonsurfactant template and catalyst. A renewable nonsurfactant template, decyl-alcohol (C10) and catalyst were used to modify the silica surfaces prior to coating with copper. In order to study the effect of catalyst on copper deposition onto silica surfaces, ammonia was used as catalyst in various amounts. The X-ray diffraction patterns of Si-Cu core-shell exhibited a broad peak corresponding to amorphous silica networks and exhibited monoclinic CuO phase. It was found that samples modified in the presence of 1 ml catalyst exhibited relatively homogeneous deposition. The surface area of uncoated core (SiO2) was at ca. 7.04 m2/g and coated samples 1 ml catalyst was at ca. 8.21m2/g.

Photoluminescence properties study of the Au/Au2S nanoshell

2002 ◽  
Vol 80 (6) ◽  
pp. 707-711
Author(s):  
J J Diao ◽  
F S Qiu ◽  
G D Chen ◽  
C Xi ◽  
Y Song
Keyword(s):  
Size Effect ◽  
Quantum Size Effect ◽  
Experimental Results ◽  
Nanometer Scale ◽  
Core Shell ◽  
Photoluminescence Properties ◽  
The Core ◽  
Enhanced Photoluminescence ◽  
Quantum Size ◽  
Photoluminescence Peak

Photoluminescence experimental results of the Au/Au2S nanoshell (a nanometer-scale Au2S core coated by a thin Au shell) are presented in this note. An enhanced photoluminescence peak of Au coated Au2S is obtained near the blue–green region, compared with the photoluminescence region of bulk Au2S, which is near the orange–red region. The quantum-size effect and the core/shell nanostructure caused the blueshift photoluminescence of the Au2S/Au nanoshell. PACS Nos.: 81.05Ys, 78.55-m

Facile synthesis of core–shell structured ZrO 2 @SiO 2 via a modified Stöber method

2016 ◽  
Vol 42 (6) ◽  
pp. 7583-7592 ◽  
Author(s):  
Ailing Bai ◽  
Hao Song ◽  
Gaoyin He ◽  
Qingsong Li ◽  
Chong Yang ◽  
...  
Keyword(s):  
Core Shell ◽  
Facile Synthesis ◽  
Stöber Method ◽  
Modified Stöber Method
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