Synthesis of hollow silica and titania nanospheres

A study was conducted to analyze wet chemical synthesis of monodisperse hollow silica and titania nanospheres. Polystyrene beads with an amine functionalized surface (APS) were used as the basic catalyst template for synthesis of nanospheres. Hollow silica nanospheres were prepared using calcination or dissolution of the APS core with organic solvents. Calcination was also used for removing the polystyrene core in the synthesis processes. Hydrolyzed tetramethoxysilane (TMOS) was applied as the precursor for the silica shell. TMOS was hydrolyzed in hydrochloric acid to enable silicic acid as the precursor of silica. Scanning electron microscopy (SEM) photographs were used to observe agglomerates of the silica particles of varying sizes. Results show that wet chemical synthesis is a suitable process to prepare nanospheres that can be used in biomedicine, catalysis, and material science.