scholarly journals Effect of various amount of ammonium hydroxide on morphology of silica nanoparticles grown by sol-gel

2018 ◽  
Vol 14 ◽  
pp. 482-484
Author(s):  
Farah Shahirah Norazmi ◽  
Kashif Tufail Chaudhary ◽  
Elham Mazalan ◽  
Zuhaib Hader ◽  
Jalil Ali
Keyword(s):  
Silica Nanoparticles ◽  
Sol Gel ◽  
Ammonium Hydroxide ◽  
Ammonia Solution ◽  
Tetraethyl Orthosilicate ◽  
Ammonium Hydroxide Solution ◽  
Monodisperse Silica ◽  
Cell Coating ◽  
Hydrolysis Of

Silica nanoparticles have drawn significant intentions for their potential in solar cell coating applications. These products occupy a noticeable position in a scientific research because of their easy preparation and wide uses for different technological applications. The quality of silica nanoparticles are highly dependent on the size. This study reports the synthesis of monodisperse silica nanoparticles by hydrolysis of tetraethyl orthosilicate (TEOS) in a mixture of ethanol and DI water as a solvent and ammonium hydroxide solution (NH4OH) as a catalyst. The solutions are stirred overnight and dried in a low-pressure furnace under 100 mbar for 3 hours at 60°C. Various-sized silica nanoparticles in the range 80 nm – 250 nm were examined under field emission scanning electron microscopy (FESEM). With the increasing volume of ammonia solution, an increase in the size of silica nanoparticles were observed. 

A Direct Route to Active Silica Nanoparticles

2007 ◽  
Vol 121-123 ◽  
pp. 65-68
Author(s):  
X.Q. Chen ◽  
Y.Y. Liu ◽  
K.H. Qi ◽  
X. Zhou ◽  
J.H. Xin
Keyword(s):  
Aqueous Solution ◽  
Silica Nanoparticles ◽  
Sol Gel ◽  
Silica Particles ◽  
Second Step ◽  
Gel Method ◽  
Direct Route ◽  
Monodisperse Silica ◽  
Acidic Conditions ◽  
Hydrolysis Of

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.

Preparation and characterization of monodisperse silica nanoparticles via miniemulsion sol–gel reaction of tetraethyl orthosilicate

2017 ◽  
Vol 52 (21) ◽  
pp. 12706-12716 ◽  
Author(s):  
Quoc-Thai Pham ◽  
Zong-Han Yao ◽  
Yun-Ting Wang ◽  
Yu-Ting Wu ◽  
Chorng-Shyan Chern
Keyword(s):  
Silica Nanoparticles ◽  
Sol Gel ◽  
Tetraethyl Orthosilicate ◽  
Monodisperse Silica

Synthesis of Fluorinated Silica Nanoparticles and the Wetting Prevention Ability

2012 ◽  
Vol 535-537 ◽  
pp. 415-418
Author(s):  
Fan Yang ◽  
Dong Yan Tang ◽  
Yu Di Guo
Keyword(s):  
Silica Nanoparticles ◽  
Tetraethyl Orthosilicate ◽  
Synthesis Conditions ◽  
Liquid Marble ◽  
The Stability ◽  
Hydrolysis Of

Fluorinated silica nanoparticles (FSNs) were synthesized by the hydrolysis of tetraethyl orthosilicate and fluoroalkyl siloxane, and by the assistance of surfactant of cetyltriammonium bromide (CTAB) under basic condition. Through adjusting the synthesis conditions, the better particles distribution of fluorinated silica could be obtained. Then the FSNs were used to prepare liquid marble with water and the stability of the liquid marble was tested to investigate the wetting prevention ability of the fluorinated silica nanoparticles.

scholarly journals Mechanistic Investigation of Sol–Gel Reactions Using Alkoxysilane Precursor

2020 ◽  
pp. 25-31
Author(s):  
Adam Hassan Elhaj Yousif ◽  
Mohammed Sulieman Ali Eltoum
Keyword(s):  
Ftir Spectroscopy ◽  
Condensation Reaction ◽  
Sol Gel ◽  
Ammonium Hydroxide ◽  
Hydrolysis Reaction ◽  
Base Catalyst ◽  
Initial Stage ◽  
Mechanistic Investigation ◽  
Sol Gel Process ◽  
Hydrolysis Of

The present study has been carried out to investigate the mechanisms of sol–gel reactions using TEOS as precursor in the presence of acid or base catalyst. The gels were prepared by hydrolysis of TEOS using hydrochloride acid or ammonium hydroxide catalyst. The obtained gels were also characterized by FTIR spectroscopy. The results of FTIR spectroscopy indicated the existence of silanol and siloxane bonds; due to the formation of hydrolyzed species as reactive intermediate compounds in initial stage converted by condensation reactions to gels as ultimate products. Accordingly, appropriate mechanisms have been proposed for sol – gel reaction using TEOS as precursor in the presence of acid or base catalyst. These mechanisms involve three-steps SN2 mechanisms for base catalyzed hydrolysis reaction of TEOS and SN1 mechanisms for acid catalyzed hydrolysis reaction of TEOS. Three mechanisms have been also proposed for condensation reaction as second stage in sol-gel process. These mechanisms include alcoxolation, oxolation and oltaion.

Effect of Ca/P Ratio on the Dissolution of Calcium Phosphate Powders

2007 ◽  
Vol 342-343 ◽  
pp. 661-664 ◽  
Author(s):  
Jong Kook Lee ◽  
Dae Sung Song ◽  
Kyu Hong Hwang ◽  
Dong Seok Seo
Keyword(s):  
Calcium Phosphate ◽  
Biomedical Applications ◽  
Ammonium Hydroxide ◽  
Ammonia Solution ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Precipitation Reaction ◽  
Hard Tissue ◽  
Ammonium Hydroxide Solution ◽  
Tissue Replacement

Calcium phosphate ceramics (CPC) have been attractively used in different areas of biomedical applications, such as substances of artificial hard tissue replacement implants, drug delivery system due to their biocompatibility and bioactivity. In this work, three calcium phosphate powders between Ca/P molar ratio 1.50-1.67 were synthesized by aqueous precipitation method, using the mixture of Ca(NO3)2·4H2O and H3PO4 solutions to ammonia solution. During the precipitation reaction, Ca/P molar ratio was adjusted by controlling pH of the solution between 8.0 and 10.5 by the addition of ammonium hydroxide solution. All powders were treated at 800 oC for 2 hrs. The calcined powders were immersed in pH 7.4 distilled water at 37°C for 3 and 7 days. Decomposition and related dissolution with the various Ca/P ratios were investigated by XRD, FTIR, and TEM observation.

scholarly journals Thermoluminescence (TL) response of silica nanoparticles subjected to 50 Gy gamma irradiation.

2017 ◽  
Vol 13 (3) ◽  
Author(s):  
Nik Noor Aien Mohamed Abdul Ghani ◽  
Mohammad Alam Saeed ◽  
Izyan Hazwani Hashim
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silica Nanoparticles ◽  
Gamma Rays ◽  
Sol Gel ◽  
Ammonia Solution ◽  
Deionized Water ◽  
Pure Silica ◽  
Transmission Electron ◽  
Size And Morphology

Thermoluminescence (TL) response of silica nanoparticles synthesized by the sol-gel method is presented here. Transmission electron microscopy (TEM) was used to find out the size and morphology of the pure silica nanoparticles. By using an appropriate amount of tetraethylorthosilicate, ethanol, deionized water and ammonia solution, silica samples were synthesized. To determine the best TL response of silica, samples were irradiated with 50Gy gamma rays. The effect of size dependency towards TL yield indicates that decreasing the particles’ size of silica, increases the TL yield.

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