The structural groups of alkali silicate glasses determined from 29Si MAS-NMR

Hideki Maekawa, Takashi Maekawa, Katsuyuki Kawamura, Toshio Yokokawa

Research output: Contribution to journalArticle

498 Citations (Scopus)

Abstract

Lithium, sodium and potassium silicate glasses containing 20-56 mol% alkali oxide were investigated by 29Si nuclear magnetic resonance (MAS-NMR) spectroscopy. In the spectrum of each sample, at least two to four distinct peaks were identified. The distributions of SiO4 structural units, Qn, where n is the number of bridging oxygen atoms bound to other Si atoms, were determined as a function of composition. The equilibrium constants of the reactions, 2Qn ⇌ Qn-1 + Qn+1 (n = 3, 2, 1), were determined. The reaction proceeds to the right direction as cationic power of alkali ion (Z/r) increases (Li+>Na+>K+) at the same alkali oxide concentration. The apparent equilibrium constants of the above reactions are discussed along with a proposed thermodynamic model. The 29Si chemical shifts assigned to each structural unit increase linearly with alkali oxide contents. The slope of these lines decreases as the numbers of attached bridging oxygen (BO) atoms decrease. The average chemical shifts also increase linearly with an increase of alkali content. A close relationship between the average chemical shifts and the theoretical optical basicity was observed.

Original languageEnglish
Pages (from-to)53-64
Number of pages12
JournalJournal of Non-Crystalline Solids
Volume127
Issue number1
DOIs
Publication statusPublished - 1991
Externally publishedYes

Fingerprint

Silicates
Chemical shift
Alkalies
alkalies
silicates
Equilibrium constants
Nuclear magnetic resonance
Glass
Atoms
nuclear magnetic resonance
Oxides
glass
chemical equilibrium
Magnetic resonance spectroscopy
Oxygen
oxides
Alkalinity
oxygen atoms
potassium silicates
Nuclear magnetic resonance spectroscopy

ASJC Scopus subject areas

  • Ceramics and Composites
  • Electronic, Optical and Magnetic Materials

Cite this

The structural groups of alkali silicate glasses determined from 29Si MAS-NMR. / Maekawa, Hideki; Maekawa, Takashi; Kawamura, Katsuyuki; Yokokawa, Toshio.

In: Journal of Non-Crystalline Solids, Vol. 127, No. 1, 1991, p. 53-64.

Research output: Contribution to journalArticle

Maekawa, Hideki ; Maekawa, Takashi ; Kawamura, Katsuyuki ; Yokokawa, Toshio. / The structural groups of alkali silicate glasses determined from 29Si MAS-NMR. In: Journal of Non-Crystalline Solids. 1991 ; Vol. 127, No. 1. pp. 53-64.
@article{a7c54c440edd4fcfb2f8713fb92429be,
title = "The structural groups of alkali silicate glasses determined from 29Si MAS-NMR",
abstract = "Lithium, sodium and potassium silicate glasses containing 20-56 mol{\%} alkali oxide were investigated by 29Si nuclear magnetic resonance (MAS-NMR) spectroscopy. In the spectrum of each sample, at least two to four distinct peaks were identified. The distributions of SiO4 structural units, Qn, where n is the number of bridging oxygen atoms bound to other Si atoms, were determined as a function of composition. The equilibrium constants of the reactions, 2Qn ⇌ Qn-1 + Qn+1 (n = 3, 2, 1), were determined. The reaction proceeds to the right direction as cationic power of alkali ion (Z/r) increases (Li+>Na+>K+) at the same alkali oxide concentration. The apparent equilibrium constants of the above reactions are discussed along with a proposed thermodynamic model. The 29Si chemical shifts assigned to each structural unit increase linearly with alkali oxide contents. The slope of these lines decreases as the numbers of attached bridging oxygen (BO) atoms decrease. The average chemical shifts also increase linearly with an increase of alkali content. A close relationship between the average chemical shifts and the theoretical optical basicity was observed.",
author = "Hideki Maekawa and Takashi Maekawa and Katsuyuki Kawamura and Toshio Yokokawa",
year = "1991",
doi = "10.1016/0022-3093(91)90400-Z",
language = "English",
volume = "127",
pages = "53--64",
journal = "Journal of Non-Crystalline Solids",
issn = "0022-3093",
publisher = "Elsevier",
number = "1",

}

TY - JOUR

T1 - The structural groups of alkali silicate glasses determined from 29Si MAS-NMR

AU - Maekawa, Hideki

AU - Maekawa, Takashi

AU - Kawamura, Katsuyuki

AU - Yokokawa, Toshio

PY - 1991

Y1 - 1991

N2 - Lithium, sodium and potassium silicate glasses containing 20-56 mol% alkali oxide were investigated by 29Si nuclear magnetic resonance (MAS-NMR) spectroscopy. In the spectrum of each sample, at least two to four distinct peaks were identified. The distributions of SiO4 structural units, Qn, where n is the number of bridging oxygen atoms bound to other Si atoms, were determined as a function of composition. The equilibrium constants of the reactions, 2Qn ⇌ Qn-1 + Qn+1 (n = 3, 2, 1), were determined. The reaction proceeds to the right direction as cationic power of alkali ion (Z/r) increases (Li+>Na+>K+) at the same alkali oxide concentration. The apparent equilibrium constants of the above reactions are discussed along with a proposed thermodynamic model. The 29Si chemical shifts assigned to each structural unit increase linearly with alkali oxide contents. The slope of these lines decreases as the numbers of attached bridging oxygen (BO) atoms decrease. The average chemical shifts also increase linearly with an increase of alkali content. A close relationship between the average chemical shifts and the theoretical optical basicity was observed.

AB - Lithium, sodium and potassium silicate glasses containing 20-56 mol% alkali oxide were investigated by 29Si nuclear magnetic resonance (MAS-NMR) spectroscopy. In the spectrum of each sample, at least two to four distinct peaks were identified. The distributions of SiO4 structural units, Qn, where n is the number of bridging oxygen atoms bound to other Si atoms, were determined as a function of composition. The equilibrium constants of the reactions, 2Qn ⇌ Qn-1 + Qn+1 (n = 3, 2, 1), were determined. The reaction proceeds to the right direction as cationic power of alkali ion (Z/r) increases (Li+>Na+>K+) at the same alkali oxide concentration. The apparent equilibrium constants of the above reactions are discussed along with a proposed thermodynamic model. The 29Si chemical shifts assigned to each structural unit increase linearly with alkali oxide contents. The slope of these lines decreases as the numbers of attached bridging oxygen (BO) atoms decrease. The average chemical shifts also increase linearly with an increase of alkali content. A close relationship between the average chemical shifts and the theoretical optical basicity was observed.

UR - http://www.scopus.com/inward/record.url?scp=0025798212&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0025798212&partnerID=8YFLogxK

U2 - 10.1016/0022-3093(91)90400-Z

DO - 10.1016/0022-3093(91)90400-Z

M3 - Article

VL - 127

SP - 53

EP - 64

JO - Journal of Non-Crystalline Solids

JF - Journal of Non-Crystalline Solids

SN - 0022-3093

IS - 1

ER -