Micrometer-sized mesoporous silica spheres grown under static conditions

Mesoporous silica spheres ranging from 2 to 6 μm in size were synthesized under static acidic conditions by mixed cationic−nonionic surfactant templating. The mesoporous structure of the calcined silica microspheres was characterized by X-ray diffraction (XRD) and nitrogen sorption, whereas the morphology and size of the microspheres were revealed by scanning electron microscopy (SEM). It was shown that stirring is unfavorable for the formation of silica spheres in the present synthesis. The growth of the micrometer-sized mesoporous silica spheres was examined by transmission electron microscopy (TEM), and an undirectional aggregation process was proposed for the formation of these spheres.