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Alteration zones of archeological glasses often show intriguing lamellar patterns in backscattered electron images. Here, we report results of static glass corrosion experiments with two different silicate glasses that revealed laminar porosity and subordinately chemical patterns inside silica-based corrosion zones that resemble those seen in naturally altered, ancient glasses. Aside from common laminar patterns, more complex patterns were observed in corrosion zones that developed along a fracture network. The formation of such patterns cannot be explained by any of the existing glass corrosion models. We suggest that silica-based corrosion zones form by a process that involves the congruent dissolution of the glass network, which is spatially and temporally coupled to the deposition of amorphous silica at an inwardly moving reaction interface. The patterns likely form in response to fluctuations of the pH and salinity in the interfacial solution, which govern the silica solubility, deposition, and dissolution rate, and thus, its microstructure and porosity, and, in turn, are controlled by the dissolution rate of the glass and the transport properties of the silica reaction layers. However, the exact feedback mechanism producing pH fluctuations in the interfacial solution has not yet been identified and is an open question for future research.

Borosilicate glasses are the favored material for immobilization of high-level nuclear waste (HLW) from the reprocessing of spent fuel used in nuclear power plants. To assess the long-term stability of nuclear waste glasses, it is crucial to understand how self-irradiation affects the structural state of the glass and influences its dissolution behavior. In this study, we focus on the effect of heavy ion irradiation on the forward dissolution rate of a non-radioactive ternary borosilicate glass. To create extended radiation defects, the glass was subjected to heavy ion irradiation using 197Au ions that penetrated ~50 µm deep into the glass. The structural damage was characterized by Raman spectroscopy, revealing a significant depolymerization of the silicate and borate network in the irradiated glass and a reduction of the average boron coordination number. Real time, in situ fluid-cell Raman spectroscopic corrosion experiments were performed with the irradiated glass in a silica-undersaturated, 0.5 M NaHCO3 solution at temperatures between 80 and 85 °C (initial pH = 7.1). The time- and space-resolved in situ Raman data revealed a 3.7 ± 0.5 times increased forward dissolution rate for the irradiated glass compared to the non-irradiated glass, demonstrating a significant impact of irradiation-induced structural damage on the dissolution kinetics.

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