The kinetic features of monodisperse spherical silica particle formation are investigated by dynamic light scattering in a model system based on the hydrolysis of tetraethoxysilane in an organic medium. The analysis of the experimental data reveals three distinct stages of silica particle formation: I) condensation of hydroxysilanes yielding di- and trimers; II) formation of branched polymeric structures; III) spatial packing of the resulting structures into final silica spheres (globules). It is demonstrated that the minimum hydrodynamic radius of silica particles detected during nucleation is independent of the synthesis conditions and is approximately 8 nm. The established patterns of existence of the stages of formation of spherical silica particles and the associated possibility of controlling their duration will in the future make it possible to program the size and degree of monodispersity of spheres, optimize the methods of introducing the necessary elements into the structure of particles, and improve the technologies for creating nanocomposite materials based on them.
Kamashev et al. (Wed,) studied this question.