PRECIPITATION OF AgCl CRYSTALS ON THE SURFACE OF ALUMINO-BOROSILICATE GLASS BY ION-EXCHANGE

An alumino-borosilicate glass containing nanosized AgCl particles was prepared by ion exchange. The original melt-cast glass only contained Cl ions and silver ions were introduced through a post-ion exchange process. Line scanning analysis of cross sectional areas showed Ag+ and K+ ions entering the glass structure, and probably loss of Li+ ions. Based on SEM results of the heat-treated glasses, it was deduced that this compositional modification encouraged liquid-liquid phase separation in ion-exchanged glasses and caused their opalescence to occur at a lower temperature compared to the traditional method. Precipitation of nanosized AgCl crystalline particles during post-heat treatment of ion-exchanged glasses induced a photochromism effect in them.