Faceted single crystals of mesoporous silica SBA-16 from a ternary surfactant system: surface roughening model

We have synthesized mesoporous silica SBA-16 at room temperature and low pH condition by using the surfactant system C8TMAB/SDS/F127 as template. Faceted single crystals of rhombdodecahedron form can be obtained under well-controlled conditions. Synthetic factors in controlling the morphology, including stirring, water content, the ionic surfactants and acidity are explored. A schematic theory for the formation of the equilibrium crystal structure based on surface roughening transition is proposed to explain the formation of faceted single crystal.