Effects of irradiation on the mechanisms controlling the residual rate of an alumino-borosilicate glass

Abstract

The alteration of a four-oxide alumino-borosilicate glass close to International Simple Glass (ISG) was studied in Si saturation conditions at pH 3, pH 7, and pH 9 using solution and post mortem solid analyses. In particular, the study examined the impact of structural disorder on the glass alteration generated by swift heavy ion irradiation. It is shown that the pre-irradiated glass altered three to four times more than the non-irradiated glass, depending on the pH. This increased alteration can be attributed to two factors: an increased hydrolysis speed of the Si–O–B bonds, which control the glass dissolution under these Si saturation conditions, and a less passivating alteration layer. The latter effect suggests that the glass structural disorder is retained by the first gel formed, which means very low Si atom mobility during alteration. However, gel maturation tends to mitigate the detrimental effect of radiation damages. These results will contribute to the development of a predictive residual rate model.

Radiation effects on the structure and alteration behavior of an SiO2–Al2O3–B2O3–Na2O glass

“…At 90 • C and pH 9, r 0 (pristine) and r 0 (irradiated) were estimated to be ∼2.46 and 14.22 ± 4.3 g m −2 d −1 , respectively. The r 0 (pristine) is in agreement with the other experimental data reported in the literature, including a recent submitted paper by Gin et al 37 The irradiated glass is estimated to dissolve ∼5.6 times faster than the pristine one. Lönartz et al 53 reported a three-time increase in the initial dissolution rate for a sodium borosilicate glass subjected to similar irradiation beams and corroded at 85 • C and pH 7.…”

“…Solution analysis and ToF-SIMS profiles are in good agreement with the recent experiments conducted under similar conditions by Gin et al 37 for CJ2 glass composition. Even though the initial rate of glass dissolution, as seen in previous section, was five times faster for the irradiated CJ2 and the layer thickness was two to four times higher for irradiated CJ2, the global mechanism followed for the gel layer formation was the same, that is, partial hydrolysis and in situ reorganization.…”

“…ET(B) for the irradiated CJ2 (∼4-5 µm) is almost two to three times higher than for the pristine CJ2 (∼2 µm). The gel layer thickness for pristine CJ2 is in agreement with Gin et al 37 The gel layer thickness 27 Al MAS and MQMAS NMR spectra of nonirradiated (pristine) and irradiated CJ2 powders. Part (A) shows the MAS NMR spectra and (B) the isotropic projection of the MQMAS spectra (see Figure S5).…”

“…At the end, the crater depth was measured with a 3D profilometer. For more details about the application of the ToF‐SIMS technique to glass alteration, see Gin et al 37 …”

Diminished Diffusion in the Aged Hydrated Gels of Irradiated Borosilicate Glasses

“…Simulation results also suggest that gels tend to retain the memory of irradiation-induced disorder post hydration and continue to possess a higher reactivity. Recent experiments by Gin et al 41 on irradiated and pristine glass composition in a silica-enriched medium showed a higher decrease in the residual rate of dissolution for irradiated glass as compared to non-irradiated. They suggested higher reactivity of post irradiated glasses led to faster dissolution and redeposition; furthermore, maturation of the gel layer was also quicker, thus offering quicker passivation and a lower residual rate.…”