A mechanism of corrosion-induced roughening of glass surfaces

Atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and solution analysis by inductively coupled plasma mass spectrometry (ICP-MS) were used to investigate the molecular scale processes responsible for the roughening of glass surfaces due to aqueous corrosion. The study of atomically smooth fiber and melt surfaces allowed direct investigation of the atomic and molecular scale effects of dissolution on surface roughness. The combined use of these analytical techniques clearly showed that the change in RMS roughness with aqueous corrosion could be directly related to the concentration of silica released to solution from the glass; cation leaching alone did not generate detectable roughening. It is well known that nano-/microscale surface roughness can influence strength, optical response, adsorptivity, and other surface properties of glass. It is shown here that the roughening of silicate glass surfaces can be expected based on the amount of silica released from the glass and does not show a dependence on the extent of modifier ion leaching. It is also suggested that the glass composition dependence of this roughening may be a measure of the nanoscale heterogeneity of the glass network structure.