Investigation of alkali ion exchange processes in waste glasses using Rutherford backscattering spectrometry and nuclear reaction analysis

A series of dissolution experiments using isotopic labeled $(D2 18O)$ aqueous solution were carried out to investigate the ion exchange mechanism in $Na2O-Al2O3-SiO2$ glasses with fixed $Na2O$ and variable $Al2O3$ concentrations. The sodium removal and the deuterium and oxygen uptake in the glass coupons were measured using ion beam methods such as Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA). Both RBS and NRA experimental spectra were simulated using the SIMNRA simulation code with a thin layer approximation. Na, D, and $18O$ concentrations as a function of depth in reacted and non-reacted glasses were determined using simulated spectra. On the basis of the depth distributions of these elements, three different zones (reaction, transition, and diffusion zones) were identified in both samples.