EFFECTS OF GLASS STRUCTURE ON THE CORROSION BEHAVIOR OF SODIUM-ALUMINOSILICATE GLASSES

The leaching and dissolution behavior of two sodium-aluminosilicate gl asses, with structures containing one versus five non-bridging oxygen sites per 10 tetrahedra, is discussed for both acid (pH 2) and base (p H 9) reactions. The soda concentration was held constant at 25 mol%. X -ray photoelectron spectroscopy, secondary ion mass spectroscopy and F ourier transform infrared reflection spectroscopy have been used to de termine the composition and structure of the reacted glass surfaces. T he glass with five NBO sites per 10 tetrahedra exhibits extensive surf ace layer formation in both acid and base. Conversely, the glass with one NBO site per 10 tetrahedra exhibits total dissolution in acid; in base, this glass is essentially unreactive. (C) 1997 Elsevier Science B.V.