Preparation of multilayered organic-inorganic hybrid core-shell particles by stepwise surface formation

This paper introduces a stepwise formation method for micro-sized, multilayered core-shell particles comprising an inorganic core, organic inner shell, and inorganic outer shell. A silica core was coated with a polystyrene seed layer, followed by surface seed polymerization with styrene, to afford the inner shell. These particles were then coated with a silica outer shell by a surface sol-gel reaction with tetraethoxysilane. The versatility of this combined surface seed polymerization and sol-gel method is emphasized by the precise control achieved over particle diameter as well as shell thickness and count. Moreover, the organic inner shell can be readily eliminated to afford a single-core-containing micro-capsular structure.