Reactivity of SiCl and SiF groups in SiO2 glass with mobile interstitial O2 and H2O molecules

Understanding the Parameters Affecting the Photoluminescence of Silicon Nanoparticles

“…Surface Si−Cl oxidation to SiO x by O 2 (g) and/or small amounts of H 2 O is spontaneous due to their large negative change in the Gibbs free energy, in analogy to SiCl 4 oxidation. 42 An average BUSiNP particle size of 1.7 ± 0.8 nm was estimated by TEM (see Supporting Information TEM), in agreement with reported sizes (1.6−1.8 nm) for SiNPs synthesized by similar chemical wet methods involving inverse micelles. 11,13 SAXS experiments with toluene suspensions of BUSiNP indicate the presence of a distribution of particles with different sizes/shapes as indicated by the upward curvature of the Guinier plot obtained from the scattering curves (see Figure 2a).…”

“…Both IR and XPS data agree in indicating that the surface of freshly prepared particles is chlorinated and is partially oxidized to SiO x upon aging. Surface Si–Cl oxidation to SiO x by O 2 (g) and/or small amounts of H 2 O is spontaneous due to their large negative change in the Gibbs free energy, in analogy to SiCl 4 oxidation …”

Investigations on the effects of mouthrinses on the colour stability and surface roughness of different dental bioceramics

“…F, as a deteriorating anion for Si is the most important element for the main ingredient of bioceramics of interest for this study. Therefore, to some extend, SiF 4 may be formation which is perhaps responsible for the corrosion of the bioceramic 1213. Organic acids such as citric acid (as in lemon, apple and peppermint) and benzydamine hydrochloride as in many vitamin and drugs can easily deform the surface of ceramic composites, which then results in color change.…”

“…Therefore, to some extend, SiF 4 may be formation which is perhaps responsible for the corrosion of the bioceramic. 12 13 Organic acids such as citric acid (as in lemon, apple and peppermint) and benzydamine hydrochloride as in many vitamin and drugs can easily deform the surface of ceramic composites, which then results in color change. Mouthrinse solutions as well as soft drinks, including tea and coffee, often give their colour to restorative materials due to the organic dye content which either enter into the nano pores of ceramics and polymers or absorbs onto the surface.…”

Surface corrosion mechanism of ceramic proppant caused by formation water

“…SiCl 4 can rapidly hydrolyze to form silica sol when it meets water, and then the silica sol rapidly forms an opaque gel, 28,29 and the corresponding reaction equation is presented in Equation (). In addition, SiCl 4 can rapidly hydrolyze to produce silicic acid gel as contact with water, 30,31 and the reaction equation is displayed in Equation (). $$$$\begin{equation}4C{l^ - } + Si{O_2} + 4{{\mathrm{H}}^ + } \to SiC{l_4} + 2{H_2}O\end{equation}$$$$ $$$$\begin{equation}SiC{l_4} + 2{H_2}O \to Si{O_2} + 4HCl\end{equation}$$$$ $$$$\begin{equation}SiC{l_4} + 4{H_2}O \to {H_4}Si{O_4} + 4HCl\end{equation}$$$$…”