Mesoporous and microporous monodispersed silica spheres have been prepared using a simple one-step synthetic procedure from an aqueous reaction mixture consisting of a commercial sodium silicate solution, various Pluronic triblock copolymers, and HCl or HNO3. The formation of porous silica spheres 130−225 μm in diameter was observed over a moderately wide range of reaction conditions. The pore structures of the resultant spheres lacked any long-range order, although they did exhibit outer textural uniformity. We concluded that the well-defined spherical morphology and pore sizes were the result of a combined effect of the EO/(EO + PO) block ratio and molecular weight of the Pluronics and the counteranions of the acid source.

Thiol-functional porous silica spheres with 100-μm mean diameter were synthesized in one quick step for ca. 60 min at room temperature using 1-alkylamine templating through the S+X-I+ assembly pathway under an acidic condition. Thiol groups were introduced into materials while mesoporous silica spheres were prepared. SEM observation revealed that dodecylamine templating afforded a higher particle-shape quality than octylamine templating. Pore size and surface hydrophilicity of organic-functional silica spheres systematically decreased with increasing coverage of thiol groups on the pore surface, but the specific area was relatively constant. Thiol-functionalized silica spheres with 40% thiol loading resulted in microporous materials with hydrophobic pore surfaces for water vapor adsorption.