Effects of the concentrations of precursor and catalyst on the formation of monodisperse silica particles in sol–gel reaction

2011 ◽  
Vol 46 (11) ◽  
pp. 2064-2069 ◽  
Author(s):  
Chul Oh ◽  
Seung-Bo Shim ◽  
Yong-Geun Lee ◽  
Seong-Geun Oh
2019 ◽  
Vol 94 (1) ◽  
pp. 186-194
Author(s):  
Qiuhua Wang ◽  
Huiying Wang ◽  
Yaling Wu ◽  
Lingping Cheng ◽  
Lunan Zhu ◽  
...  

2007 ◽  
Vol 121-123 ◽  
pp. 65-68
Author(s):  
X.Q. Chen ◽  
Y.Y. Liu ◽  
K.H. Qi ◽  
X. Zhou ◽  
J.H. Xin

Monodisperse silica particles containing available active C=C bonds were directly prepared by a simple two-step sol-gel method. In the first step the hydrolysis of vinyltrimethoxysilane (VTMS) was performed under acidic conditions in an aqueous solution. In the second step the condensation of the siloxane precursors progressed under basic conditions, resulting in production of silica nanoparticles containing available active C=C bonds. The products were characterized using SEM and FTIR.


Langmuir ◽  
2004 ◽  
Vol 20 (7) ◽  
pp. 2523-2526 ◽  
Author(s):  
S. H. Kim ◽  
B. Y. H. Liu ◽  
M. R. Zachariah

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 463
Author(s):  
Srecko Stopic ◽  
Felix Wenz ◽  
Tatjana-Volkov Husovic ◽  
Bernd Friedrich

Silica has sparked strong interest in hydrometallurgy, catalysis, the cement industry, and paper coating. The synthesis of silica particles was performed at 900 °C using the ultrasonic spray pyrolysis (USP) method. Ideally, spherical particles are obtained in one horizontal reactor from an aerosol. The controlled synthesis of submicron particles of silica was reached by changing the concentration of precursor solution. The experimentally obtained particles were compared with theoretically calculated values of silica particles. The characterization was performed using a scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS). X-ray diffraction, frequently abbreviated as XRD, was used to analyze the structure of obtained materials. The obtained silica by ultrasonic spray pyrolysis had an amorphous structure. In comparison to other methods such as sol–gel, acidic treatment, thermal decomposition, stirred bead milling, and high-pressure carbonation, the advantage of the ultrasonic spray method for preparation of nanosized silica controlled morphology is the simplicity of setting up individual process segments and changing their configuration, one-step continuous synthesis, and the possibility of synthesizing nanoparticles from various precursors.


2002 ◽  
Vol 726 ◽  
Author(s):  
Yongsoon Shin ◽  
Jun Liu ◽  
Li-Qiong Wang ◽  
Jeong Ho Chang ◽  
William D. Samuels ◽  
...  

AbstractWe here report the synthesis of ordered ceramic materials with hierarchy produced by an in-situ mineralization of ordered wood cellular structures with surfactant-templated sol-gel at different pH. At low pH, a silicic acid is coated onto inner surface of wood cellular structure and it penetrates into pores left, where degraded lignin and hemicellulose are leached out, to form a positive replica, while at high pH the precipitating silica particles due to fast condensation clog the cells and pit structures to form a negative replica of wood. The calcined monoliths produced in different pHs contain ordered wood cellular structures, multi-layered cell walls, pits, vessels well-preserved with positive or negative contrasts, respectively. The surfactant-templated mineralization produces ordered hexagonal nanopores with 20Å in the cell walls after calcination.


2004 ◽  
Vol 29 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Yasushi Murakami ◽  
Kazuhiko Tanaka ◽  
Yusuke Takechi ◽  
Saki Takahashi ◽  
Yuuki Nakano ◽  
...  

2000 ◽  
Vol 613 ◽  
Author(s):  
Sun Hyuk Bae ◽  
Jae-Hyun So ◽  
Seung-Man Yang ◽  
Do Hyun Kim

ABSTRACTSilica slurry used as abrasives in wafer polishing process is made by dispersing silica particles in an alkali solution. Since commercially available colloidal or fumed silica particles need some modifications to be directly used as abrasive slurry due to their small sizes, irregular shapes or broad size distribution, we have prepared silica abrasives by particle growth of fumed silica or colloidal silica as seeds by sol-gel method. Silica slurries prepared by this step-wise growth from commercial seeds were tested using one-armed polisher for the comparison with commercial slurries and showed the performance comparable to commercial slurries. Microstructures of polishing slurries were investigated using transmission electron microscopy and ARES rheometer. From the result, stability of the slurry was found to be more important than the primary particle sizes for the polishing performance.


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