Formation mechanism of SBA-16 spheres and control of their dimensions

Abstract

Using a quaternary mixture of surfactant F127, demineralized water, HCl and butanol, it is possible to form different sized spheres of SBA-16 only by controlling the amount of siliceous precursor (TEOS) used during the synthesis. These spheres are well ordered and show very high porosity. The size of the spheres can be explained by an agglomeration mechanism of colloidal SBA-16 particles and a consequent filling of the interparticle voids with amorphous silica. The existence of the colloidal particles as well as the formation of partially formed (agglomerated) spheres and the filling of the voids is evidenced by SEM. All materials were characterized using N2-sorption, X-ray diffraction and scanning electron microscopy.