Chemistry of Glass "Part 7": NMR Spectroscopy in the Analysis of Glass.

Spectroscopy known as nuclear magnetic resonance, or NMR, is based on the interaction of an external magnetic field and the magnetic moment of an atom's nucleus.

NMR Stopped Flow Probe

For the study of materials, and notably glasses, solid-state NMR is a crucial technique nowadays, and because there is no order in the atomic arrangements of this amorphous substance (Glass), specialized analytical instruments are needed.
A challenge that must be taken into account in order to describe and comprehend the experimental spectra of glasses is the enlargement; the structural and chemical disorder in NMR leads to an enlargement of the resonances around an average characteristic frequency since the studied interactions are local at the atomic scale.

The local molecular structure of glass and its physical and chemical characteristics are closely connected; macroscopic characteristics like viscosity, chemical durability, conductivity, mechanical resistance, etc, are related directly to the proportion of non-bridging oxygen in the glass. Which implies that multiple details on the structure of oxide glasses are provided by a nucleus like oxygen17. It enables the identification of the depolymerized regions containing the alkaline and alkaline-earth ions, producing the non-bridging oxygen necessary for the compensation of the electrical charges as well as the different chemical bonds that make up the vitreous network's backbone.

Bridging oxygen and non-bridging oxygen

References:

• [General and inorganic chemistry book- M. Shkhashirou- H. Birqdad- Y. Qodsi- University publications. Algeria]
• Glass and Ceramic Technology Course (2021). Professor Khelifa- Department of Materials Process Engineering- University of Mostaganem. Algeria.
• Les matériaux au cœur du processus d'innovation- Clefs CEA No 59.
• Neumann, Florin. "Glass: Liquid or Solid – Science vs. an Urban Legend". Archived from the original on 9 April 2007. Retrieved 8 April 2007.
• Helène Tregouët. Structure et cristallisation de verres d’oxydes simples riches en bore et en terres rares. Chimie-Physique [physics.chem-ph]. Université Pierre et Marie Curie- Paris VI, 2016. Français. NNT: 2016PA066032. tel-01358710.