Present understanding of R7T7 glass alteration kinetics and their impact on long-term behavior modeling

Mathematical Formulation Requirements and Specifications for the Process Models

“…A large amount of information on the glass-water reaction collected over the past 25 years has been summarized in the "glass compendium" (Cunnane, 1994) and numerous reviews (Barkatt et al, 1986;Bourcier, 1991Bourcier, , 1994Bunker et al, 1988;Casey and Bunker, 1990;Hench et al, 1986;Icenhower et al, 2004;McGrail et al, 1997;Strachan and Croak, 2000;Vernaz and Dussossoy, 1992;Vernaz et al, 2001;Werme et al, 1990). Based on these reviews, the glass dissolution reaction can be divided into four regimes or stages (Figure 1) that occur as the reaction proceeds (e.g., Stage I, II, III, and IV).…”

Durability of Silicate Glasses: An Historical Approach

“…H 3 O + ions exchange at a very high rate (the "initial rate") with available network modifiers that are water soluble, such as alkalis (but also alkaline-earths and divalent transition elements). This so-called "interdiffusion" effect is initially intense but quickly reaches a steady state with time [5], except possibly in closed systems after long exposures [12]. In a closed system, the pH will locally increase at the interface because of the formation of silanol groups (Si-OH) and the leaching of "free" aqueous ions that were formerly network modifiers [1][2][3][4][5][6][7].…”

“…Glass resistance to weathering is a concern for geochemists and material scientists (interested in nuclear and municipal wastes) who have conducted a large number of fundamental studies on the dissolution rates of a variety of oxide glasses and the concomitant metal ion leaching that occurs on the glass surface [1][2][3][4][5]. Glass weathering also has a significant impact on historical glasses, particularly stained glasses and archeological glasses.…”

“…Glass weathering also has a significant impact on historical glasses, particularly stained glasses and archeological glasses. Stained glasses are encountered in monuments (usually religious) from the early Middle Ages to the present, with a large production during the gothic period (XIth-XVth centuries) [5][6][7][8][9][10][11]. These stained glasses were mostly exposed to attacks by atmospheric gases.…”

“…These artifacts were exposed to chemical corrosion by various fluids and gases for durations lasting from centuries to millenia. This timescale is therefore of special interest because it falls between those achievable in laboratories (days-months-years) [4][5] and those observable in nature (geological glasses weathered over thousands to millions of years) [4]. In addition, historical glasses have unique reaction conditions relative to laboratory-treated and geologic glasses, including exposure to urban environments (dusts, diesel particles, acid rains, mass tourism) and climatic variables (continental vs. temperate, Siberian vs. Mediterranean, etc.)…”