Impact of initial states on the vapor hydration of iodine-bearing borosilicate glass

International audienceUnder the context of long-term geological disposal of nuclear waste glass, the present work investigates the effectof initial states on the glass chemical durability in the vapor phase and during subsequent leaching. Glass withdifferent finishing steps of polishing and thermal annealing were prepared, vapor-hydrated, and aqueous-altered.Multiple characterizations of mechanical properties and structural modifications were performed to understandthe reduction of vapor hydration rates with annealed glasses. Discussions on the degradation of mechanicalproperties provide insights to understanding the variations of glass chemical durability, which shows a feasibleapproach to link mechanical and chemical studies together. By looking into the release of boron in the vaporphase, similarities between glass vapor hydration and glass aqueous alteration at residual rate are noticed, whichallow the proposition of mechanisms of boron release. Characterizations of the hydrated-then-altered glass revealthe transport-limiting property of the vapor hydrated layer