Understanding the mechanisms of Si–K–Ca glass alteration using silicon isotopes

Long-term weathering rate of stained-glass windows using H and O isotopes

“…The vapor circulation from the external surface to the alteration front is confirmed by the isotopic tracing experiment (using D 2 18 O), and the corresponding mapping of D and 18 O distribution are carried out by NanoSIMS. All the enrichment values are Fig.…”

“…EV1 and OU2 samples were exposed for 1 day at 90% RH and 20°C under doped water vapor (D 2 18 O). The isotopic distribution inside the alteration layer reveals the presence and the homogeneity of the isotopic enrichments, from the external surface to the pristine glass interface (Table 1).…”

“…6,7 It leads to the formation of a hydrated and dealkalinized layer that can be reorganized by local hydrolysis / condensation reactions. 2,8,9 In the second case, an interfacial dissolutionprecipitation process is proposed to explain the gel formation, notably on nuclear glass. [10][11][12] More consensually, the secondary phases are formed by the precipitation of dissolved elements of the glass and/or elements of the environment.…”

“…35 In this way, in contrast to the nuclear glasses, the influence of the pore closure over time on the alteration rate drop is expected to be low. Thus, the aim of the study is to trace water vapor circulation (using doped water in D 2 18 O) within the alteration layer of ancient stained-glass windows (already altered during 650 years) in order to assess its role and to investigate the progress of alteration to measure the long-term kinetics in unsaturated conditions.…”

“…Alteration of glass in aqueous media has been extensively studied in various contexts such as the geological storage of vitrified radioactive wastes, the contribution of basaltic glass dissolution to biogeochemical cycles, or the conservation of historical artifacts (e.g., [1][2][3][4] and references therein). Water is the main agent in glass degradation.…”