Silica nanostructures are sophisticatedly designed by interlayer alkoxysilylation of layered silicates (magadiite and kenyaite) with alkoxytrichlorosilanes and the subsequent hydrolysis of alkoxy groups. The dichlorosilyl groups of alkoxytrichlorosilanes [(RO)ClSiCl2] were reacted onto two neighboring Si-OH groups on the surface of the layered silicates to form a bridge, leaving two functional (Si-OR and Si-Ci) groups on the bridge. The remaining bifunctional groups were almost completely hydrolyzed to transform into Si-OH groups. Depending on the solvent for hydrolysis, the hydrolyzed product derived from magadiite forms either a new 3-D silicate structure by condensation of interlayer silanol groups or a new 2-D silicate structure by geminal Si-OH groups remaining immobilized on both sides of the silicate layers. The 3-D silicate structure exhibits microporosity (130 m 2 g-1) and hydrophilic behavior. On the other hand, the hydrolyzed product from kenyaite takes only a 2-D silicate structure, even when the solvents for hydrolysis were completely evaporated.
ASJC Scopus subject areas
- Materials Chemistry