particles, which result in irregular arrangements. These
results show that at higher calcination temperatures and
longer aging times, a bigger particle size has been produced.
FESEM micrographs of these particles are shown
in Fig. 2 and Fig. 3, which demonstrate that the spherical
silica nanoparticles have been successfully synthesized
via this method. These micrographs illustrate the surface
morphology of samples aged during 2 h, 4 h and 6 h at
calcination temperatures of 600 C and 700 C.