Ion-exchange-induced Phase Separation at Dot-like Domains on Glass Surface through a Staining Method

Staining, which has been used for coloring of glass, was extended as a method for ion exchange in which monovalent ions in the localized fine domains at the surface of glass are replaced by other ions contained in the stain. Here, mixed aqueous LiNO3-poly(ethylene glycol) solution was deposited as dots approximately 100 mu m in diameter on a 70SiO(2)center dot 15B(2)O(3)center dot 15Na(2)O (mol %) glass by ink-jet printing. Then the glass was heat-treated at 400 degrees C resulting in the exchange of Li+ for Na+ ions at the dot-like domains. This ion exchange induced phase separation at the dots. Subsequent heat treatment at 600 degrees C and acid leaching made the dot domains porous. Consequently, we succeeded to prepare a glass, at the surface of which dot-like domains were porous and a number of the dots are periodically arrayed.