Synthesis of monodisperse spherical silica particles with solid core and mesoporous shell: Mesopore channels perpendicular to the surface

Both particle monodispersity and mesopore orientation have been considered in this work. Monodisperse spherical silica particles with a solid core and a mesoporous shell featuring mesopore channels perpendicular to the core surface were synthesized for the first time by adopting silica particles as the core component and by employing C_n-TAB (n = 12, 14, 16, 18), the structure-directing agent for the mesoporous shell. Micelles on the surface of the silica particles are formed from the electrostatic interaction between the partially negatively charged silica particles and the positively charged surfactant molecules under basic conditions. The particles synthesized in this work have a uniformly coated thin mesoporous shell of about 28-61 nm in thickness over the silica core and possess a surface area of ca. 370-500 m ² g^-1, pore volume of ca. 0.2-0.35 cc g^-1, and narrow pore size distribution.