A General Mechanism for Gel Layer Formation on Borosilicate Glass under Aqueous Corrosion
- Univ. of Montpellier, Marcoule (France). Alternative Energies and Atomic Energy Commission (CEA), CEA Nuclear Energy Division (DEN), Department on Technologies for Enrichment, Decommissioning and Waste (DE2D)
- Univ. of Huddersfield, Huddersfield (United Kingdom)
- TESCAN Analytics, Fuveau (France)
- Inst. de Radioprotection et de Sûreté Nucléaire (IRSN), Fontenay-aux-Roses (France)
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Mineral and glass dissolution is a scientific topic that has been deeply investigated but is not understood completely; it continues to be of great interest in the geochemical and materials science communities. If the interfacial dissolution/reprecipitation mechanism seems to be applicable to most silicate minerals, the debate remains open concerning glass. Here, we studied two model glasses, a ternary borosilicate (CJ1) and the same glass doped with 4.1 mol % of Al2O3 (CJ2). The two glasses were altered at 90 °C, pH 9, and in conditions far and close to saturation with respect to amorphous silica to determine the initial and residual rates. Moreover, a specific experiment was conducted for a short duration with a solution highly enriched with 18O and 29Si isotopes to understand how passivating gels form. SEM, TEM, and ToF-SIMS characterizations along with Monte Carlo simulations were used to understand the rate limiting reactions at play and infer the role of Al. We show that Al yields a slower matrix dissolution in dilute conditions. However, it slows down the formation and the maturation of the passivating gel and favors alteration by partial hydrolysis of Si and Al entities followed by in situ reorganization/relaxation into a porous network. Unexpectedly, CJ1 experienced both interfacial dissolution/reprecipitation and partial hydrolysis followed by in situ reorganization of the silicate network during the course of a single experiment. Here, this study offers a unified concept that can pave the way for the future development of a predictive kinetic model based on a detailed description of bond breaking and bond forming as a function of glass composition and alteration conditions.
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Center for Performance and Design of Nuclear Waste Forms and Containers (WastePD); The Ohio State Univ., Columbus, OH (United States); Inst. de Radioprotection et de Sûreté Nucléaire (IRSN), Fontenay-aux-Roses (France); Alternative Energies and Atomic Energy Commission (CEA), Marcoule (France); Univ. of Huddersfield (United Kingdom); TESCAN Analytics, Fuveau (France)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- SC0016584
- OSTI ID:
- 1600946
- Journal Information:
- Journal of Physical Chemistry. C, Vol. 124, Issue 9; ISSN 1932-7447
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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