Monodispersed mesoporous silica spheres with various mesopore symmetries

Monodispersed mesoporous silica spheres (MMSS) with different mesopore symmetries, such as hexagonal, cubic, or the mixture of hexagonal/cubic, are synthesized changing synthesis conditions. It seems that the direction of mesopores is retained through the particle in MMSS with cubic symmetry. In the case of hexagonal/cubic mixed symmetry, cubic structure is observed at the center of the particle, while hexagonal structure is observed near the surface. It is assumed that cubic structure forms at early stage of the particle growth and hexagonal symmetry forms at the later stage, leading to the formation of cubic core/hexagonal shell structure.