Some Structural Features of Monodisperse Spherical Silica Particles - Structural Units of Opal Matrices

Abstract

AbstractWe studied the sedimentation rate of monodisperse spherical silica particles and the volume of the supramolecular structure formed by them which together with the data on the particle sizes allowed calculating their real density. The obtained data testified to a significant content of voids in the structure of the particle, the volumetric values of which are within 30%.The specific surface area for supramolecular structures consisting of monodisperse spherical silica particles was determined by nitrogen sorption, according to which we calculated their estimated sizes. Comparison of the results obtained with the data determined using scanning electron and atomic force microscopy, as well as by dynamic light scattering methods, showed that spherical particles had a surface area 30% higher than the theoretically calculated one which indicated the complex structure of silica particles and the presence of a system of hidden pores and voids.We interpreted the data within the framework of the assumption of hierarchical nature of structure of spherical silica particles.KeywordsSupramolecular structuresMonodisperse spherical silica particlesDensity of amorphous silica