Correlating the Morphological Properties and Structural Organization of Monodisperse Spherical Silica Nanoparticles Grown on a Commercial Silica Surface.

A variety of nanosilicas have been widely used to fabricate rough surfaces with superhydrophobic and superhydrophilic properties. In this context, we prepared mixed silica and mixed nanosilica that were generated by the growth and self-assembly of synthesized monodisperse silica nanospheres (11–30 nm, 363 m2 g−1) on the surface of Sylopol-948 and Dispercoll S3030 by using a base-catalyzed sol–gel route. Using this process, the interactions and hierarchical structure between the nano- and microsized synthesized silica particles were studied by changing the amount of tetraethoxysilane. The resulting materials were characterized by BET analysis, small-angle X-ray scattering (SAXS), dynamic light scattering, FTIR spectroscopy, and SEM. The mixed silica presented a higher specific surface area (326 m2 g−1), a six-fold higher percentage of (SiO)6 (44–68 %), and a higher amount of silanol groups (14.0–30.7 %) than Sylopol-948 (271 m2 g−1, 42.6 %, and 12.5 %, respectively). The morphological and hierarchical structural differences in the silica nanoparticles synthesized on the surface of commercial silica (micrometric or nanometric) were identified by SAXS. Mixed micrometric silica exhibited a higher degree of structural organization between particles than mixed nanosilica.