Biomedical Engineering Reference
In-Depth Information
Fig. 7.10
Multistep crystallization: (
a
) Initial dilute liquid phase. (
b
) Amorphous dense droplets
are first created from the mother phase. (
c
) A few subcrystal nuclei are created from the amorphous
phase. (
d
) A stable crystal is formed from the dense droplets. Colloidal suspension is sealed
between two pieces of ITO-coated conducting glass plates separated by insulating spacers. The
gap between the two glass plates is
H
m. The dynamic process is recorded by a
digital camera for analysis. (
b
) Phase diagram of the colloidal suspension. Monodisperse colloidal
particles (polystyrene spheres of diameter 0.99
D
120
˙
5
5%, Bangs Laboratories)
are dispersed uniformly in deionized water. In the case, the volume fraction 0.03% of colloidal
solid is chosen, and the surface potential of the colloidal spheres is adjusted to -72 mV by
Na
2
SO
4
(10
-4
M). The pH of the suspension is measured at 6.35. Monodisperse colloidal particles
are dispersed uniformly in deionized water. Reproduced with permission from Ref. [
40
] ©2003
American Chemical Society
m, polydispersity
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