A critical evaluation of barium silicate glass network polymerization.
MOULTON, Benjamin J. A.; PICININ, Adalberto; SILVA, Laís D.; DOERENKAMP, Carsten; ZARTO, Harold Lozano; SAMPAIO, David; ZANOTTO, Edgar Dutra; DU, Jincheng; ECKERT, Hellmut; PIZANI, Paulo S.
MOULTON, Benjamin J. A.; PICININ, Adalberto; SILVA, Laís D.; DOERENKAMP, Carsten; ZARTO, Harold Lozano; SAMPAIO, David; ZANOTTO, Edgar Dutra; DU, Jincheng; ECKERT, Hellmut; PIZANI, Paulo S.
Abstract: The state of polymerization in barium silicate glasses (xBaO·(1-x)SiO2, 0.28 =x =0.45) has been studied by both experiment (Raman, static and MAS 29Si NMR spectroscopy) and molecular dynamics simulations (Vashishta- Rahman and Du-Cormack potentials). No a priori assumptions were made about the number of Qn species, specific mean polymerization nor presence or absence of ?free? oxygen species. This allowed us to test the re- lationships between these structural aspects. The Qn site interconversion equilibrium constants KQ2 and KQ3 were found to be 0.07 and 0.05±0.02 from static 29Si NMR, and 0.14±0.07 and 0.07±0.01 from 29Si MAS NMR, respectively. The Qn species distribution was used to determine the Raman scattering cross-sections for Q1, Q2 and Q3 as 1.01±0.15, ~1.1, and 1.14±0.04, respectively, although some compositional dependence was found. The Q4 cross-section displays a unique behavior approaching 0 at 38% BaO. This more accurate structural framework paves the way for future studies to establish meaningful structure??property relationships for these glasses.
@article={003075923,author = {MOULTON, Benjamin J. A.; PICININ, Adalberto; SILVA, Laís D.; DOERENKAMP, Carsten; ZARTO, Harold Lozano; SAMPAIO, David; ZANOTTO, Edgar Dutra; DU, Jincheng; ECKERT, Hellmut; PIZANI, Paulo S.},title={A critical evaluation of barium silicate glass network polymerization},journal={Journal of Non-Crystalline Solids},note={v. 583, p. 121477-1-121477-19},year={2022}}