The effect of ph on the properties of silica nanoparticles / Halawati Othman

In this project, silica particles have been successfully produced by using adjusted
StOber method. Tetraethyl orthosilicate (TEOS) was used as source of silica,
Sodium Hydroxide (NaOH) as catalyst, and Cetyl Trimethylammonium Bromide
(CTAB) as pore-forming agent and surfactants. In order to study the effect of pH
on the properties of silica particles, the amount of NaOH has been adjusted to find
the different value of pH. The samples were analysed by using EDX, SEM, FTIR,
UV-Vis, and XRD. According to SEM, the size of silica particles produced is about
0.423 micrometer. From UV-Vis spectroscopy, the direct energy band gap has been
analysed by using Tauc plot. The energy band gap has been estimated for SO.10,
SO.15, SO.20, SO.25 and SO.30 samples are 3.9184, 3.9554, 3.8679, 3.9939 and
4.0695 eV respectively. Increase of energy bandgap shows the decrease of particles
size. XRD pattern shows several sharp peaks for sample SO.1 and SO.2 that defined
as crystalline structure. While, for SO.30 sample show broad peak which determine
amorphous pattern state of silica. The reaction parameters should be carefully
adjusted in order to produce high quality silica particles which suitable for
application in drug delivery