Light scattering of SiO2 monodisperse microspheres prepared by the sol-gel route

Abstract

SiO2 microspheres have been prepared from TMOS/Methanol/water sols in basic condition (pH = 12) by the Stöber method and studied by TEM static and dynamic light scattering techniques in order to determine the mean size R¯, size distribution, hydrodynamic radius R(H), radius of gyration R(G) and translational diffusion coefficient D(t) ; the ratio R(H)/R(G) was found less, than 0.55 and the aggregates have a fractal geometry with df ~ 2.3 ± 0,05. The results are compared to preivous work on colloidal silica aggregates prepared by other techniques and discussed.