Abstract:
Tetraethyl orthosilicate (TEOS) was synthesized by chemical methods from silicon
dioxide and diethyl ether using acid catalyst of hydrochloric acid (11.8M) by two
methods, direct method and by using copper oxide supported on silica catalyst. The
sol gel process was applied for the preparation of nano silica gel. This method
involves hydrolysis and condensation reaction of TEOS, the mechanism of this
method was explained and show formation of a network Si-O-Si chemical linkage
form the alkoxysilane, the yield of tetraethylorthosilicate was characterized by Fourier
transform-Infrared (FT-IR) spectroscopy, the results indicating that, the bond of Si-OSi
successfully formed. Finally the comparison between two methods was studied and
results show that, the rate of reaction of TEOS which prepared by direct method was
equal to l0.008g/sec and that which prepared by using catalyst was equal to 0.27g/sec,
this indicating that, the tetraethylorthosilicate which prepared using catalyst was
better than that prepared by direct method.
