Direct Experimental Evidence for Abundant BO4-BO4 Motifs in Borosilicate Glasses From Double-Quantum 11B NMR Spectroscopy

Yang Yu; Baltzar Stevensson; Mattias Edén

doi:10.1021/acs.jpclett.8b02907

Direct Experimental Evidence for Abundant BO₄-BO₄ Motifs in Borosilicate Glasses From Double-Quantum ¹¹B NMR Spectroscopy

J Phys Chem Lett. 2018 Nov 1;9(21):6372-6376. doi: 10.1021/acs.jpclett.8b02907. Epub 2018 Oct 24.

Authors

Yang Yu¹, Baltzar Stevensson¹, Mattias Edén¹

Affiliation

¹ Physical Chemistry Division, Department of Materials and Environmental Chemistry , Stockholm University , SE-106 91 Stockholm , Sweden.

PMID: 30354174
DOI: 10.1021/acs.jpclett.8b02907

Abstract

By using double-quantum-single-quantum correlation ¹¹B nuclear magnetic resonance (NMR) experiments and atomistic molecular dynamics (MD) simulations, we resolve the long-standing controversy of whether directly interlinked BO₄-BO₄ groups exist in the technologically ubiquitous class of alkali/alkaline-earth based borosilicate (BS) glasses. Most structural models of Na₂O-B₂O₃-SiO₂ glasses assume the absence of B^[4]-O-B^[4] linkages, whereas they have been suggested to exist in Ca-bearing BS analogs. Our results demonstrate that while B^[4]-O-B^[4] linkages are disfavored relative to their B^[3]-O-B^[3]/B^[4] counterparts, they are nevertheless abundant motifs in Na₂O-B₂O₃-SiO₂ glasses over a large composition space, while the B^[4]-O-B^[4] contents are indeed elevated in Na₂O-CaO-B₂O₃-SiO₂ glasses. We discuss the compositional and structural parameters that control the degree of B^[4]-O-B^[4] bonding.