Diffusive processes in aqueous glass dissolution
Publication Date
2019-12Journal Title
npj Materials Degradation
ISSN
2397-2106
Volume
3
Issue
1
Number
39
Language
en
Type
Article
This Version
AM
Metadata
Show full item recordCitation
Goût, T. L., Misra, S., Tipper, E., Bohlin, M. S., Guo, R., & Farnan, I. (2019). Diffusive processes in aqueous glass dissolution. npj Materials Degradation, 3 (1. 39)https://doi.org/10.1038/s41529-019-0102-5
Abstract
High level nuclear waste is often immobilised in a borosilicate glass for disposal. However, this glass corrodes in contact with aqueous solutions. To predict radionuclide releases from wasteforms, their dissolution mechanisms must be understood. Understanding glass dissolution mechanisms presents a challenge across numerous other disciplines and many glass dissolution models still remain conflicted. Here we show that diffusion was a significant process during the later stages of dissolution of a simplified waste glass but was not evidenced during the initial stages of dissolution. The absence of measurable isotopic fractionation in solution initially supports models of congruent dissolution. However, the solution becoming isotopically lighter at later times evidences diffusive isotopic fractionation and opposes models that exclude diffusive transport as a significant mechanism. The periodically sampled isotopic methodologies outlined here provide an additional dimension with which to understand glass dissolution mechanisms beyond the usual measurement of solution concentrations and, post-process, nano-scale analysis of the altered glass.
Sponsorship
EPSRC (EP/M507350/1)
EPSRC (EP/I036400/1)
Identifiers
External DOI: https://doi.org/10.1038/s41529-019-0102-5
This record's URL: https://www.repository.cam.ac.uk/handle/1810/299118
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All rights reserved