Structural study of composites of aerosil fumed silica and tetraethoxysilane-derived sonogels

Immobilized Polymer Fraction in Hyperbranched Polymer/Silica Nanocomposite Suspensions

“…The second were methacrylsilane-treated silica particles supplied in powder form with a specific surface equal to 150 ± 25 m 2 /g (AS, Aerosil R7200, Degussa). These particles were based on fumed silica aggregates of 12 nm primary particles (Aerosil 200), with a density equal to 2.2 g/cm 3 and specific surface equal to 200 m 2 /g , (values in the range 180−200 m 2 /g were also reported using BET and scattering methods). Micron-sized glass spheres (GS, Sigma-Aldrich) of size 9−13 μm and specific surface equal to ∼0.1 m 2 /g (i.e., 3 orders of magnitude smaller than the nanoparticles) were also used.…”

Effect of Mechanical Activation of Highly Disperse SiO$_{2}$/$\alpha$-Fe$_{2}$O$_{3}$ Mixtures on Distribution of Valence Electrons

“…In order to analyse the effect of mechanical activation on interatomic interactions, namely on a character of electron distributions in oxygen, silicon, and iron atoms, it is necessary to determine the energy regions, where Op, Sisd, and Fesd valence electrons localize for the studied materials. The energy distributions of valence electrons in various silicas were analysed in detail elsewhere [24][25][26]. It is shown [24][25][26], that lower subband corresponds to covalent-binding states in silica, and the high-energy OK  band describes non-binding electronic states occupied by electrons transferred from silicon to oxygen.…”

“…The energy and charge states of ions depend on energy redistribution of valence electrons of atoms of surface layers of nanoparticles with developed surface area as in nanosize SiO 2 and -Fe 2 O 3 [12][13][14][15][16][17][18][19][20][21][22][23]. Properties of such materials in nanocomposites are reciprocally supplemented [24][25][26][27]. Thus, it is important to investigate the electronic structure depending on composition of such nanomaterials and synthesis method.…”