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Updated: Jun 1, 2026
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Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Boron environments in Pyrex® glass--a high resolution, Double-Rotation NMR and thermodynamic modelling study
A P Howes1, N M Vedishcheva, A Samoson
1Department of Physics, University of Warwick, Coventry CV4 7AL, UK.
Physical Chemistry Chemical Physics : PCCP
|May 28, 2011
Summary
High-resolution (11)B Double-Rotation (DOR) NMR experiments reveal Pyrex® glass has a heterogeneous structure. This technique, combined with thermodynamic modeling, precisely maps boron environments in complex glasses.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Spectroscopy
Background:
- Understanding the complex structure of glasses like Pyrex® is crucial for material applications.
- Traditional NMR methods often suffer from line broadening, obscuring detailed structural information.
Purpose of the Study:
- To apply (11)B Double-Rotation (DOR) NMR and thermodynamic modeling to elucidate the complex structure of Pyrex® glass.
- To achieve high-resolution spectra for accurate analysis of boron coordination environments.
Main Methods:
- Utilized 1D and 2D (11)B Double-Rotation (DOR) NMR spectroscopy to minimize dipolar and quadrupolar broadening.
- Employed thermodynamic modeling (Model of Associated Solutions) to predict and validate structural units.
- Analyzed (11)B spin-diffusion DOR NMR spectra for cross-peak correlations.
Main Results:
- Achieved high-resolution (11)B DOR NMR spectra, enabling accurate assignment of boron species (B3 and B4).
- Identified specific borate and borosilicate superstructural units, including triborate, pentaborate, diborate, and boroxol rings.
- Demonstrated excellent agreement between experimental data and thermodynamic predictions for boron-containing groupings.
Conclusions:
- Pyrex® glass exhibits a heterogeneous structure with distinct molecular groupings, not a random distribution.
- (11)B DOR NMR combined with thermodynamic modeling is a powerful tool for characterizing complex glass structures.
- The findings provide a detailed structural model linking B(2)O(3)-like regions to the silica network via borate and borosilicate units.
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