Biomedical Engineering Reference
In-Depth Information
0.5
μ
m
0.5
μ
m
Figure 13.14
The SEM (upper) and TEM (lower) images of uniformed
mesoporous silica beads with radical porous structure under water-alcohol-ether
ternary system. From left to right, each fi gure shows the morphologies with
different porous structure, which indicates that the ratio of solvent may infl uence
it. (Reprinted with permission from [74])
with a pore size of about 2.0 nm and BET specifi c surface area around
726m
2
/g. These spheres were then used as seeds for one-step growth by
a semi-batch process plus surfactants, which could enlarge silica spheres
up to 2.0 μm. Furthermore, the effects of initial synthetic condition on the
morphology of MMS have been studied. It is found that the combination
of surfactant could affect the morphologies of MMS. In binary surfac-
tant system (CTAB
DDA), the diameter of the MMS of silica gradually
increases with the increase of the proportion of CTAB/CTAB
+
DDA while
keeping the other reagents constant. The cosolvent proportion also affects
the morphologies of MMS of silica. With the increase of isopropanol/H
2
O,
the size of spheres decreases gradually, conglomeration disappears, and
the monodispersity of the sphere turns as well, but many silica oligomers
appear around large spheres or connect with the spheres.
+
13.5
Conclusion and Prospective
To sum up, we have addressed concepts from biomineralization to
biomimic synthesis of mesoporous silica, and have summarized the
recent achievements on its morphological control of mesoporous silica.
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