Biomimetic Preparation and Morphology Control of Mesoporous Silica - Biomimetics: Advancing Nanobiomaterials and Tissue Engineering - page 310

13.4.2.1 Diluted Aqueous System

In the diluted solution system, MCM-41 silica particles with several morphol-
ogies have been controllably synthesized with a basic medium. By changing
the reaction factor, such as composition ratio and medium, different mor-
phologies of MCM-41 could be controllably synthesized [29, 30]. They are
nanospherical MCM-41 silica with an average size of 100 nm (which is the
fi rst synthesis of mesoporous silica nanoparticles), a submicrometer-sized
silica rod, 0.3-0.6

m in length, and micrometer-sized
oblate silica with nominal diameter around 1

μ m in diameter and 1 μ

m respectively.
Firstly, the preparation of large MCM-41 single crystals as well as their
controllable morphologies has very important meanings not only for their
potential applications but also for the exploration of the new morphoge-
netic mechanism for some special mesoporous crystals.

μ

Figure 13.6 Upper left: SEM micrographs of calcined of MCM-41 (scale bar,
3700 nm); right fi gure, scheme of the morphology control in ammonia medium in
extremely diluted system. Lower left: the high resolution TEM image of MCM-41
single crystal. Lower right: TEM image of the calcined materials: (a) nanometer
MCM-41 (scale bar, 167 nm); (b) nanometer MCM-41 (scale bar, 50 nm); (c) MCM-
41 single crystal (scale bar, 500 nm); (d) MCM-41 single crystal (scale bar, 100
nm); (e) submicrometer rod of MCM-41 (scale bar, 500 nm); (f) submicrometer
rod of MCM-41 (scale bar, 100 nm). (Reprinted with permission from [29, 30])