5. Other pathologies

5.1 Hydrolytic attack of glass

Pending operation, use or installation, glass must be stored in special conditions to prevent damage from chemical attack by water.

The alterability of glass with respect to water is linked to a phenomenon of ion exchange: on the one hand, the acceptance of H ⁺ ions from the solvent (water), and on the other, the release of Na ⁺ ions (a constituent of soda-lime glass).

The most important attack on glass is by alkaline solutions. Si–O–Si bonds are altered by NaOH (or KOH) to form Si–O–H and Si–O–Na (or Si–O–K).

The process that triggers the attack is therefore an exchange of alkaline and H...