Ion-exchange mechanisms and interfacial reaction kinetics during aqueous corrosion of sodium silicate glasses

This work investigates the atomic and nanoscale details of glass-water interfacial reactions in sodium silicate glasses using reactive force field (ReaxFF) based molecular dynamics (MD) simulations. The study elucidates key ion-exchange mechanisms and kinetics of associated interfacial reactions, finding that Na⁺ and H⁺ exchange occurs between oxygen ions on single or adjacent silicon oxygen tetrahedra. A clustered reaction of two non-bridging oxygens mediated by water is also identified, potentially the main water transport mechanism after initial surface reactions. Statistical analyses reveal silanol formation is favored over re-formation initially. The findings enhance understanding of ion-exchange mechanisms during glass hydration and glass-water interactions.

Lu Deng, Katsuaki Miyatani, Michinori Suehara, Shin-ichi Amma, Madoka Ono, Shingo Urata, Jincheng Du