Abstract
The majority of the literature on glass corrosion focuses on understanding the dissolution kinetics and mechanisms of silicate glass chemistries in the neutral-to-alkaline aqueous regime owing to its relevance in the fields of nuclear waste immobilization and biomaterials. However, understanding the corrosion of silicate-based glass chemistries over a broad composition space in the acidic pH regime is essential for glass packaging and touch screen electronic display industries. A thorough literature review on this topic reveals only a handful of studies that discuss acid corrosion of silicate glasses and their derivatives - these include only a narrow set of silicate-based glass chemistries. Although the current literature successfully explains the dissolution kinetics of glasses based upon classically understood aqueous corrosion mechanisms, more recent advancements in atomic-scale characterization techniques, have enabled a better understanding of reactions taking place directly at the pristine glass-fluid interface which has facilitated the development of a unifying model describing corrosion behavior of silicate glasses. Based on the corrosion mechanisms described and the questions raised in preceding literature, the present study focuses on understanding the corrosion mechanisms governing metaluminous (Na/Al = 1) sodium aluminoborosilicate glasses in acidic environments across a wide composition-space (ranging from SiO2-rich to B2O3-rich compositions), with particular emphasis on understanding the reactions taking place near the glass-fluid interface. Using state-of-the-art characterization techniques including nuclear magnetic resonance (NMR) spectroscopy, Rutherford backscattering, X-ray photoelectron spectroscopy (XPS) and elastic recoil detection analysis (ERDA), it has been shown that stepwise B2O3 substitutions into nepheline (NaAlSiO4) glass, although causing non-linear changes in glass structure network structural features, leads to strikingly linear increases in the forward dissolution rate at pH = 2. While the glasses undergo congruent dissolution in the forward rate regime, the residual rate regime displays evidence of preferential extraction near the glass surface (i.e., enrichment in aluminum content upon corrosion through AlO4 → Al(OH)3 evolution) implying that dissolution-re-precipitation processes may occur at the glass-fluid interface in both B2O3-rich and SiO2-rich glass compositions - albeit with vastly dissimilar reaction kinetics.
Original language | English |
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Pages (from-to) | 1881-1896 |
Number of pages | 16 |
Journal | Physical Chemistry Chemical Physics |
Volume | 22 |
Issue number | 4 |
DOIs | |
State | Published - 2020 |
Funding
This material is based upon work supported by the National Science Foundation under Grant No. 1507131, the US Department of Energy (DOE) – Offices of Nuclear Energy and Environmental Management through Nuclear Energy University Program under Grant No. DE-NE0008597, and US DOE – Office of River Protection under Grant No. DE-EM0003207. ORNL is operated by UT-Battelle, LLC, for the US DOE under Contract No.’s DE-AC05-00OR22725. The authors also thank the Characterization Sciences group at Corning Incorporated for compositional analysis of the glasses.
Funders | Funder number |
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Nuclear Energy and Environmental Management | |
Office of River Protection | DE-EM0003207 |
National Science Foundation | 1507131 |
National Science Foundation | |
U.S. Department of Energy | DE-AC05-00OR22725 |
U.S. Department of Energy | |
Nuclear Energy University Program | DE-NE0008597 |
Nuclear Energy University Program |