Thermodynamic Prediction of Spinodal Decomposition in Multi-component Silicate Glass for Design of Functional Porous Glass Materials

Abstract

The authors have investigated metastable phase separation in multi-component silicate glass for the fabrication of porous glass from multi-component slag. Spinodal decomposition forms an interconnected microstructure in glass spontaneously, and porous glass is obtained by leaching one of the decomposed phases with an acid solution. This porous glass can be used for a filter to remove impurities in polluted water or air. In this study, the metastable miscibility gap was predicted in multi-component silicate glass using thermodynamic analyses where glass was regarded as a super-cooled liquid phase. Occurrence of spinodal decomposition was observed in annealed glass, and it corresponded to the predicted miscibility gap. Then, we fabricated porous glass using spinodal decomposition in multi-component borosilicate glass and by removing one of the decomposed phases. Furthermore, for the creation of functional porous glass applicable for environmental purification, the spinodal decomposition was prepared in multi-component borosilicate glass containing titanium oxide based on the predicted metastable miscibility gap in multi-component silicate glass.

Keywords

• spinodal decomposition
• porous glass
• slag
• multi-component silicate systems
• gibbs energy