Structure and mechanical property of water-containing soda–alumina–silica glass by molecular dynamics simulation

• MD simulation of water-containing glasses was carried out for substituting Na+ ion with H+ ion and inserting H2O molecule in 22Na2O–11Al2O3–67SiO2 glass.
• The ion-substituted hydrous glass had lower packing density than H2O molecule-inserted hydrous glass.
• The ion-substituted hydrous glass deformed easily rather than H2O molecule-inserted hydrous glass.
• Mechanical property of glass deteriorates more easily with OH group rather than H2O molecule.

Structure and mechanical property of water-containing glasses were investigated with a molecular dynamics simulation. The glasses were prepared by substituting Na+ ion with H+ ion and inserting H2O molecule in 22Na2O–11Al2O3–67SiO2 glass (N-0). The number of network rings in the ion-substituted hydrous glass (NH) was independent of total water content and almost the same as that in N-0, while that in the H2O molecule-inserted hydrous glass (NM) decreased with increasing total water content due to the reaction of H2O molecules with glass network; the decomposition of H2O molecule and the breakage of the network. However, NM had denser structure than NH so that Young's modulus of NM became larger than those of NH when total water content (OH + H2O) was the same. NM deformed more slowly than NH under stress, indicating that mechanical property of glass deteriorates more easily with OH group rather than H2O molecule.