Preparation of tetraethoxysilane for the production of monodisperse spherical silica particles. Part 3. Influence of impurity elements

Nanostructured 3D matrices based on monodisperse spherical silica particles are currently of considerable interest due to the prospects for their widespread use in the synthesis of new nanocomposite materials. At the same time, one of the main problems hindering their large-scale synthesis is associated with the unstable behavior of tetraethoxysilane (TEOS) during its hydrolysis and, as a result, poor reproducibility of the sizes of the formed silica particles under given conditions. In this work, based on the study of the elemental composition of impurities in silica opal matrices obtained from tetraethoxysilane from various manufacturers, we continued to study factors affecting the size of the formed particles. To solve this problem, samples of supramolecular structures obtained from TEOS from various manufacturers were examined by the ICP-MS method for the content of impurity elements in them. It is shown that the content of elements in the initial TEOS correlates with deviations in the size of the formed silica particles. The experiments carried out on the synthesis of spherical particles with the introduction of additives of a number of previously defined elements confirm the obtained dependence. Moreover, it was found that the presence of certain impurity elements in the system increased the monodispersity of the sizes of the formed silica particles, which was a fundamentally important step to solve the problem of obtaining silica particles of a given size with high reproducibility of results. The obtained results are important for understanding the features of the formation of supramolecular structures of silica in nature.