Particle morphology and microstructure in the mesoporous silicate SBA-2

The mesoporous solid SBA- 2, prepared at room temperature in alkaline pH using the gemini surfactant [CH3(CH2)(15)N(CH3)(2)(CH2)(3)N(CH3)(3)](2+) can adopt hollow sphere (ca. 100 mum diameter), flat plate (50 mum across) and small sphere (1- 2 mum diameter) morphologies. Plates appear to be formed directly by fracturing of the hollow spheres. The nanostructure of these materials is consistent with templating around close packed micelles. X- Ray diffraction and high resolution imaging show that the structure of these preparations ranges from mainly hexagonal to mainly cubic close packing.