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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