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<p>A study was focused on 17 samples of borosilicate glasses, utilizing an eight-component model system representing the pharmacy vials with the following base glass composition: 75.23&#xa0;mol% SiO<sub>2</sub>, 7.70&#xa0;mol% B<sub>2</sub>O<sub>3</sub>, 4.24&#xa0;mol% Al<sub>2</sub>O<sub>3</sub>, 8.02&#xa0;mol% Na<sub>2</sub>O, 1.15&#xa0;mol% CaO, 1.44&#xa0;mol% K<sub>2</sub>O, 0.95&#xa0;mol% ZnO, and 1.26&#xa0;mol% BaO. The glass composition was modified through increasing and decreasing the molar amount of each oxide. For the network-forming oxides (SiO<sub>2</sub>, and B<sub>2</sub>O<sub>3</sub>), and Al<sub>2</sub>O<sub>3</sub> the content was changed by ± 10 relative %. For the modifier oxides (remaining oxides), the content was either increased by ± 40 relative % or reduced to zero. Molar Gibbs energies from the FACT database were used to evaluate the Shakhmatkin-Vedishcheva thermodynamic model (SVTDM). 115 model components were considered, of which only 25 with non-negligible equilibrium molar amounts were identified. After identification of components with strongly correlated equilibrium molar amounts, only 11 independent components remained. From the SVTDM results, the distribution of Si-Q and B-Q was calculated. Multilinear regression analysis was used to describe the dependence of molar volume (<i>V</i><sub>m</sub>) and glass transition temperature (<i>T</i><sub>g</sub>) on the equilibrium molar amounts of significant and uncorrelated SVTDM components. After excluding statistically insignificant terms for <i>V</i><sub>m</sub>, and <i>T</i><sub>g</sub>, the standard deviation of approximation s<sub>apr</sub> = 0.13&#xa0;cm<sup>3</sup> mol<sup>−1</sup>, and s<sub>apr</sub> = 1.7&#xa0;K were obtained. Subsequently, regression analysis was used to describe the dependence of <i>V</i><sub>m</sub>, and <i>T</i><sub>g</sub> on the molar amounts of the individual Q-units. In such a way, the compositional dependence of <i>V</i><sub>m</sub>, and <i>T</i><sub>g</sub> was described by a lower standard deviation of approximation; for molar volume s<sub>apr</sub> = 0.20&#xa0;cm<sup>3</sup> mol<sup>−1</sup>, and for glass transition temperature s<sub>apr</sub> = 6.2&#xa0;K. The distribution of Q-units obtained by SVTDM was found to reliably describe the compositional dependence of the selected properties of the model borosilicate glass.</p>

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Thermodynamic model and structural analysis of borosilicate glasses for pharmacy

  • 期刊论文

  • 出版模式：

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  • 发表日期：

    2025年10月28日

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  • Branislav Hruška,
  • Mária Chromčíková,
  • Aleksandra Nowicka,
  • Jan Macháček,
  • Jaroslava Gombárová,
  • Marek Liška

摘要

A study was focused on 17 samples of borosilicate glasses, utilizing an eight-component model system representing the pharmacy vials with the following base glass composition: 75.23 mol% SiO2, 7.70 mol% B2O3, 4.24 mol% Al2O3, 8.02 mol% Na2O, 1.15 mol% CaO, 1.44 mol% K2O, 0.95 mol% ZnO, and 1.26 mol% BaO. The glass composition was modified through increasing and decreasing the molar amount of each oxide. For the network-forming oxides (SiO2, and B2O3), and Al2O3 the content was changed by ± 10 relative %. For the modifier oxides (remaining oxides), the content was either increased by ± 40 relative % or reduced to zero. Molar Gibbs energies from the FACT database were used to evaluate the Shakhmatkin-Vedishcheva thermodynamic model (SVTDM). 115 model components were considered, of which only 25 with non-negligible equilibrium molar amounts were identified. After identification of components with strongly correlated equilibrium molar amounts, only 11 independent components remained. From the SVTDM results, the distribution of Si-Q and B-Q was calculated. Multilinear regression analysis was used to describe the dependence of molar volume (Vm) and glass transition temperature (Tg) on the equilibrium molar amounts of significant and uncorrelated SVTDM components. After excluding statistically insignificant terms for Vm, and Tg, the standard deviation of approximation sapr = 0.13 cm3 mol−1, and sapr = 1.7 K were obtained. Subsequently, regression analysis was used to describe the dependence of Vm, and Tg on the molar amounts of the individual Q-units. In such a way, the compositional dependence of Vm, and Tg was described by a lower standard deviation of approximation; for molar volume sapr = 0.20 cm3 mol−1, and for glass transition temperature sapr = 6.2 K. The distribution of Q-units obtained by SVTDM was found to reliably describe the compositional dependence of the selected properties of the model borosilicate glass.