Chemical durability of lead crystal glass: Comparison of short‐term aqueous and atmospheric alteration at 90°C

• Published in: International journal of applied glass science 2021-01, Vol.12 (1), p.158-174
• Main Authors: Collin, Marie, Diallo, Babacar, Lecoq, Hélène, Ory, Sandra, Chauvet, Elodie, Pellerin, Nadia
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Artists; Atomic structure; Chemical Sciences; Crystals; Glass; Hydroxyl groups; Leaching; NMR spectroscopy; Oxygen atoms
• ISSN: 2041-1286; 2041-1294
• DOI: 10.1111/ijag.15843

Crystal glass alteration in an aqueous medium has been extensively studied following the implementation of strict regulations regarding lead leaching. However, despite the widespread use of lead glasses and crystal glass by artists and artisans ever since antiquity, few works focus on crystal glass corrosion in atmospheric conditions. In this preliminary study, the altered layers formed on crystal glass in aqueous and atmospheric conditions at 90°C are compared. On the timescale studied (20 days), ToF‐SIMS profiles of both altered layers show water ingress. This hydration step is correlated with K leaching in aqueous media, and 29Si and 27Al NMR analysis of the altered structure highlights the formation of new Q4 and AlO6 units. Low alkali leaching is observed in atmospheric conditions, but the altered glass structure is highly hydrolyzed, as attested by its high water and silanol content. As a result, the altered layer formed in aqueous conditions is more polymerized than the one formed in atmospheric conditions, and potentially more passivating through a mechanism involving water availability. On the bases of 29Si/1H and 27Al/1H CP‐MAS NMR experiments, the oxygen repartition is described in the altered glasses, differentiating the oxygen atoms involved in structural NBO from that of hydroxyl groups.