Structure of sodium silicate water glass—X-ray scattering experiments and force-field molecular dynamics simulations

• Published in: Journal of non-crystalline solids Vol. 579; p. 121370
• Main Authors: Noritake, Fumiya, Sato, Tomoko, Yamamoto, Akane, Wakabayashi, Daisuke, Urakawa, Satoru, Funamori, Nobumasa
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-03-2022
• Subjects: Molecular dynamics; Small-angle X-ray scattering; Sodium silicate glass; Water glass; NMR; Water glass; MD; Molecular dynamics; FSDP; Sodium silicate glass; NBO; BO; Small-angle X-ray scattering; SAXS
• ISSN: 0022-3093; 1873-4812
• DOI: 10.1016/j.jnoncrysol.2021.121370

Sodium silicate water glass is used in various applications as adhesives and lubricants. Herein, we used X-ray scattering experiments and force-field molecular dynamics (MD) simulations to investigate the structure of sodium silicate water glass. The concentrated sodium water glass had a low-Q pre-peak; in contrast, the diluted glass did not, as observed from X-ray scattering experiments. The intensity of the low-Q peak decreased with an increase in pressure. MD simulations provided a structure of sodium silicate water glass with sodium clusters surrounded by hydrated silicate anions at low pressures. These sodium clusters were the origin of the low-Q peaks in the simulated patterns. The sodium clusters dissolved in water with an increase in pressure, and consequently, the intensity of the low-Q peak drastically decreased.