Sarayut Termnak. Study of sonication effect and stabilization of TiO2 Nanoparticles by Polyacrylamide . Master's Degree(Polymer Science and Technology). Mahidol University. : Mahidol University, 2007.
Study of sonication effect and stabilization of TiO2 Nanoparticles by Polyacrylamide
Abstract:
Segregation of agglomerated particles using ultrasonics and stabilization of TiO2
nanoparticles by polyacrylamide (PAM) were studied. Conventional TiO2 NP was dried and
kept in powder form. However, because the small particles have high surface energy and are
susceptible to forming agglomerates, the particle size of TiO2 increases when used as
suspension. Size reduction of the agglomerates into nanometer particle of TiO2 is necessary
before usage. PAM was chosen in this experiment because it can be used to stabilize
suspension under both acidic and basic conditions. Furthermore, it is non-toxic and widely
used with biological systems. The agglomerate size reduction by sonication of synthesized
TiO2 (S-TiO2) was also studied in comparison to commercial TiO2 (C-TiO2). The result shows
that agglomerate size of TiO2 can be reduced with high sonication power (>15 micron of
amplitude) and low rotor speed (<2500 rpm). In addition, the use of PAM is able to help
stabilizes TiO2 in suspension after segregation of agglomerates for over 1 month. Without the
use of PAM stabilization, TiO2 NP precipitated within 2 days. Moreover, S-TiO2 has smaller
primary particle size than C-TiO2. However, S-TiO2 has higher agglomeration than C-TiO2,
and cannot be segregated even with high power sonication.