Page 123 - Book Hosokawa Nanoparticle Technology Handbook

2.5 PORE STRUCTURE FUNDAMENTALS

10nm 100nm

Figure 2.5.8
Porous SiO particles prepared by removing PSL particles after it arranged via self-organization process.
2
30 organized pores, the ratio between the size of the sil-
ica nanoparticles size, d, and the PSL size, D, must be
Successful
known to be lower than d/D 0.155.
Unsuccessful
SiO 2 diameter, d (nm) 20 100nm PSL particles mixed precursor. Since the titania
Figure 2.5.10 shows an SEM image of porous tita-
nia particles prepared from titania nanoparticles and
nanoparticles used are not monodispersed and some
are in an agglomerated condition, the porous arrange-
ment in the particles is not as good as the result
10
size of the PSL particles used is relatively larger, well-
100nm obtained for the porous silica particles. However, if the
organized porous particles can be easily prepared.
The phenomena of the porous arrangement in par-
0
0 50 100 150 200 ticles prepared by the present method can be
explained quantitatively by the topology theory [10].
PSL diameter, D (MM)
Particles having a porous structure are of interest
Figure 2.5.9 because of their potential applications such as in opti-
Preparation conditions for obtaining successful ordered cal functional particles, oral inhalation drug particles,
porous SiO particles. etc. To control the porous structure, a spray-drying
2

300nm 300nm

PSL diameter : 100nm PSL diameter : 207nm
Figure 2.5.10
Porous titania particles prepared from the mixed solution of titania nanoparticles and PSL particles.

99