scholarly journals Synthesis and Surface Properties of Silica Spheres with Core Shell Structure by One Convenient Method

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
D. P. Das ◽  
K. M. Parida ◽  
B. K. Mishra
Keyword(s):  
Mesoporous Silica ◽  
Shell Structure ◽  
Cost Effective ◽  
Molar Ratio ◽  
Ammonium Bromide ◽  
Core Shell ◽  
Silica Spheres ◽  
Core Shell Structure ◽  
Cetyltrimethyl Ammonium ◽  
Mesoporous Silica Spheres

Earlier, we have published a paper on the preparation of silica sphere using propanol as cosurfactant. We report here a highly cost-effective method of preparation of mesoporous silica spheres with core shell structure using sodium silicate as silica precursor, cetyltrimethyl ammonium bromide (CTAB) as surfactant, and methanol as cosurfactant. Thus after removal of the template by dissolutions or/and activation at higher temperature, mesoporous silica spheres with core shell structure were obtained. The products prepared with methanol to CTAB molar ratio 8.5 : 1 were confirmed to give best results. All the spherical products have very large surface area (∼589–1044 m2/g), pore volume (∼0.98–1.41 cm3/g), and ordered pore structure.

Synthesis of Highly Monodispersed Core/Shell Mesoporous Silica Spheres

2006 ◽  
Vol 45 ◽  
pp. 814-818
Author(s):  
Kazuhisa Yano ◽  
Tadashi Nakamura ◽  
Hiroshi Nozaki ◽  
Noritomo Suzuki ◽  
Yuusuke Akimoto
Keyword(s):  
Mesoporous Silica ◽  
Particle Surface ◽  
Core Shell ◽  
Silica Spheres ◽  
Laser Scattering ◽  
Monodispersed Particles ◽  
Core Shell Structure ◽  
Mesoporous Silica Spheres ◽  
Scattering Measurement

Particle size development of monodispersed mesoporous silica spheres (MMSS) was investigated by laser scattering measurement, TEM and XRD in situ. Smaller particles suddenly appeared after the commencement of the experiment, then growing homogeneously to larger particles. It is assumed that residual silica precursors in solution preferentially reacted with existing particle surface silanol, preventing generation of new particles. This leads to the formation of monodispersed particles. Based on the mechanism, monodispersed mesoporous silica spheres with core/shell structure have been newly synthesized.

Formation Mechanism for Monodispersed Mesoporous Silica Spheres and Its Application to the Synthesis of Core/Shell Particles

2006 ◽  
Vol 111 (3) ◽  
pp. 1093-1100 ◽  
Author(s):  
Tadashi Nakamura ◽  
Mamoru Mizutani ◽  
Hiroshi Nozaki ◽  
Noritomo Suzuki ◽  
Kazuhisa Yano
Keyword(s):  
Mesoporous Silica ◽  
Formation Mechanism ◽  
Core Shell ◽  
Silica Spheres ◽  
Shell Particles ◽  
Mesoporous Silica Spheres

Nanocomposites of CsPbBr3 perovskite nanocrystals in an ammonium bromide framework with enhanced stability

2017 ◽  
Vol 5 (30) ◽  
pp. 7431-7435 ◽  
Author(s):  
Sunqi Lou ◽  
Tongtong Xuan ◽  
Caiyan Yu ◽  
Mengmeng Cao ◽  
Chao Xia ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ion Exchange ◽  
Shell Structure ◽  
Water Resistance ◽  
Ammonium Bromide ◽  
Core Shell ◽  
Excellent Thermal Stability ◽  
Long Lifetime ◽  
Core Shell Structure ◽  
Enhanced Stability

The CsPbBr3@NH4Br nanocomposites were successfully synthesized through ion exchange. The nanocomposites possessed a special core@shell structure and exhibited a high absolute PLQY, long lifetime, good water resistance and excellent thermal stability.

One-step synthesis of core-shell structured mesoporous silica spheres templated by protic ionic liquid and CTAB

2016 ◽  
Vol 178 ◽  
pp. 35-38 ◽  
Author(s):  
Shuo Zhao ◽  
Yiwei Zhang ◽  
Yuming Zhou ◽  
Xiaoli Sheng ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Mesoporous Silica ◽  
Core Shell ◽  
Silica Spheres ◽  
Protic Ionic Liquid ◽  
One Step ◽  
Mesoporous Silica Spheres

scholarly journals Design of Scorodite@Fe3O4 Core–Shell Materials and the Fe3O4 Shell Prevents Leaching of Arsenic from Scorodite in Neutral and Alkaline Environments

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 523
Author(s):  
Yang Wang ◽  
Zhihao Rong ◽  
Xincun Tang ◽  
Shan Cao
Keyword(s):  
Photoelectron Spectroscopy ◽  
Shell Structure ◽  
Molar Ratio ◽  
Alkaline Solutions ◽  
Arsenic Content ◽  
Core Shell ◽  
X Ray ◽  
Core Shell Structure ◽  
The Stability ◽  
Fe3o4 Core

In recent years, arsenic pollution has seriously harmed human health. Arsenic-containing waste should be treated to render it harmless and immobilized to form a stable, solid material. Scorodite (iron arsenate) is recognized as the best solid arsenic material in the world. It has the advantages of high arsenic content, good stability, and a low iron/arsenic molar ratio. However, scorodite can decompose and release arsenic in a neutral and alkaline environment. Ferroferric oxide (Fe3O4) is a common iron oxide that is insoluble in acid and alkali solutions. Coating a Fe3O4 shell that is acid- and alkali-resistant on the surface of scorodite crystals will improve the stability of the material. In this study, a scorodite@Fe3O4 core–shell structure material was synthesized. The synthesized core–shell material was detected by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Raman, and energy-dispersive X-ray spectroscopy (EDS) techniques, and the composition and structure were confirmed. The synthesis condition and forming process were analyzed. Long-term leaching tests were conducted to evaluate the stability of the synthesized scorodite@Fe3O4. The results indicate that the scorodite@Fe3O4 had excellent stability after 20 days of exposure to neutral and weakly alkaline solutions. The inert Fe3O4 shell could prevent the scorodite core from corrosion by the external solution. The scorodite@Fe3O4 core–shell structure material was suitable for the immobilization of arsenic and has potential application prospects for the treatment of arsenic-containing waste.

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