TEMPERATURE-INDUCED CHANGES IN THE COMPOSITION OF FLOATGLASS SURFACES

Floatglass is an important kind of commercial glass, comprising the ma in body of modern flat glass used in buildings and vehicles. The stoic hiometry of the surface layer differs from that of the bulk and will u sually change due to subsequent high-temperature process steps or atta ck by water or humidity. Glass samples have been investigated by means of ion beam analysis. Using resonant nuclear reaction analysis (N-15 technique), hydrogen concentration profiles have been determined. Prof iles of the heavier glass constituents, especially sodium and tin, hav e been obtained by RES. Changes in the composition of the floatglass s urfaces caused by subsequent temperature treatment (up to 700 degrees C) and by controlled hydration treatment are reported. Possible mechan isms of hydrogen uptake and release are discussed.