The Atomic Structure of a Metal‐Supported Vitreous Thin Silica Film

Abstract

Clear as glass: The atomic structure of a metal-supported vitreous thin silica film was resolved using low-temperature scanning tunneling microscopy (STM). Based on the STM image, a model was constructed and the atomic arrangement of the thin silica glass determined (see picture). The total pair correlation function of the structural model shows good agreement with diffraction experiments performed on vitreous silica.

Silica Surface Features and Their Role in the Adsorption of Biomolecules: Computational Modeling and Experiments

“…For mesoporous silicas a figure of 4 nm -2 has been reported by Trébosc et al 83 from TG and 29 Si NMR (see section 3.1.5); also from TG and 29 Si NMR, Landmesser et al 84 have evaluated the percentage of Si atoms bearing OH groups and while there is some ambiguity regarding the surface area of their material, a figure in the range 4.2 to 4.6 nm -2 has been estimated.…”

“…Since the first stages of its development, solid-state NMR has been a choice technique in the study of the local structure of silicates and silica polymorphs, 72 since 29 Si is a "good" nucleus for NMR because it has a ½ nuclear spin, it provides well-resolved spectra without the complications due to quadrupolar interactions, and 29 Si chemical shifts (δ) are highly sensitive to details of the molecular environment (for instance, a correlation between δ and the average Si-O-T angle was evidenced early on). Thus, 29 Si NMR provides valuable information on the bulk structure.…”

“…Thus, 29 Si NMR provides valuable information on the bulk structure. Whether it allows to specifically observe surface groups depends first and foremost on the surface area: if this parametre is too low, surface-specific signals will be overwhelmed by bulk ones.…”

“…Figure 11. Typical (1-pulse) 29 Si MAS-NMR spectrum of a fumed silica (Aerosil 380), with band assignments. Adapted from Ref.…”

“…147 which proposes a CP quantification technique. Recently, an improvement in surface selectivity more spectacular than that observed with CP was shown using dynamic nuclear polarisation (DNP), where a 100-fold enhancement of the surface 29 Si signals was observed for a mesoporous silica. 148 This technique involves contacting the sample with a small amount of radical-containing solution, which is not chemically innocuous, and it is too early to tell what impact it will have on the field.…”