what could be the mechanism (reason) for the formation of meso scale pores in silica nanoparticles prepared through the Stober's "Sol-Gel" methods
Dear Chander,
do you mean the modified Stober which yields mesoporous silica or the Stober synthesis which yields hard silica spheres with pours?
I mean, Stober synthesis which yields hard silica spheres with pours?
To form a structure of nano silica spheres with mesopores, you need surfactant (e.g. CTAB) and silica source (e.g.TEOS). In water solution, CTAB self assembled into micelle. At this time the TEOS hydrolyzed into silica nanoparticles around the CTAB micelle. Removing the CTAB by calcination leaves the remained SiO2 with mesopores. That's why people often call surfactant like CTAB the template agent.
Chander obviously refers to the established fact that Stöber silica particles have some porosity, not mesoporous, but much smaller pores. The smaller the particles the higher the degree of porosity. So far I understand the particles are formed through TEOS hydrolysis followed by condensation. The particles grow from the inside to the outside where the condensed structures are less compact at the outside.
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