DIRECT OBSERVATION OF THE SHELL-LIKE STRUCTURE OF SiO2 PARTICLES SYNTHESIZED BY THE MULTISTAGE STÖBER METHOD

Abstract

Ultramicrotomy was used to prepare a cross-section of shell-like amorphous SiO2 spherical particle synthesized by the multistage Stöber method which allowed performing first direct observations of the hierarchical structure of the SiO2 particle by transmission and scanning electron microscopy. The presence of primary, secondary and tertiary particles forming the inner structure of SiO2 spheres was established. The use of the small angle scattering of neutrons and synchrotron radiation techniques has enabled to define the size of the primary particles, the fractal parameters of their surface and the bulk density of the SiO2 spheres.