A proposal of the source and the evolution of the bubble in the glass melts. Molecular orbital and molecular dynamics studies

Abstract The formation of the bubble in the manufacturing process of the glass is one of the most serious problems on the production of the high quality commercial products, and the source and the evolution process of the bubble in the glass melts still remain unclear. According to our speculation that the clustered gas molecules in the glass melts grow to the bubble, we focused on the clustering of the N 2 molecules with the cations Na + , Mg 2+ , and Al 3+ included in the glass melts in the manufacturing process. Our ab initio MO (B3LYP) calculations showed that the N 2 molecules strongly bind to the cations, Na + , Mg 2+ , Al 3+ , by both electrostatic and the charge transfer interactions between the N 2 molecules and the cations. However, the binding among the N 2 molecules is extremely weak without the cations. The aggregation of the N 2 molecules at the cations was also successfully simulated in the assumed glass melts by the classical molecular dynamics method. These theoretical analyses are discussed in detail.