In Situ Production of Spherical Silica Particles Containing Self-Organized Mesopores

Nano Letters ◽  
2001 ◽  
Vol 1 (5) ◽  
pp. 231-234 ◽  
Author(s):  
Ferry Iskandar ◽  
Mikrajuddin ◽  
Kikuo Okuyama
2013 ◽  
Vol 773 ◽  
pp. 606-610
Author(s):  
Jing Li ◽  
Hong Qi Zhang ◽  
Wei Xue

Spherical silica particles, with mean sizes about 1.2 μm, were prepared through TEOS sol-gel process catalyzed by ammonia. The silica particles have a smooth surface and a small specific surface area, 3.4 m2/g. The sol-gel process was monitored by React IRTMusing an in-situ technique. Based on the measurements, mechanism of TEOS hydrolyzation and succedent condensation polymerization was inferred. With the adding of ammonia, OH-anion attacks Si atomic nucleus directly and makes it showing negative electricity. Therefore the electron cloud shifts to the OR group on the other side. This weakens the Si-O bond and results in the removal of the OR group. Furthermore, silanol, generated from TEOS hydrolyzation, attracts Si-OR or other Si-OH around; thereby resulting rapid dehydration or dealcohol between molecular. So the condensation polymerization rate is elevated, and Si-O-Si bond comes into being. Lastly, cross-linking reaction among Si-O-Si bonds forms the particle.


RSC Advances ◽  
2021 ◽  
Vol 11 (28) ◽  
pp. 17108-17115
Author(s):  
Mahnaz Mirheidari ◽  
Javad Safaei-Ghomi

GO@f-SiO2@Co is a heterogenous catalyst composed of spherical silica particles grafted on the surface of graphene oxide with ethylenediamine ligands and coordination with Co(ii). We assessed the activity of the catalyst for the synthesis of aminonaphthoquinones.


2004 ◽  
Vol 69 (9) ◽  
Author(s):  
P. Tartaj ◽  
T. González-Carreño ◽  
O. Bomatí-Miguel ◽  
C. J. Serna ◽  
P. Bonville

1987 ◽  
Vol 3 (1) ◽  
pp. 86
Author(s):  
Yasuo Azuma ◽  
Yoshimi Tajima ◽  
Nobuo Ōshima ◽  
Kensuke Suehiro

2015 ◽  
Vol 41 (3) ◽  
pp. 316-323 ◽  
Author(s):  
E. Yu. Stovpiaga ◽  
D. A. Kurdyukov ◽  
Yu. A. Kukushkina ◽  
V. V. Sokolov ◽  
M. A. Yagovkina

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