Dissolution of LnYSiAlO glass (Ln=La or Ce) in aqueous media. I. Influence of the pH on hydrolysis mechanisms and kinetics

Dissolution of LnYSiAlO glass (Ln=La or Ce) in aqueous media. II. Influence of heavy ion irradiation on mechanisms and rate of hydrolysis

“…3, NL Si values are very weak in the case of LaY glass (NL(i) Si and NL(ni) Si < 100 lg/cm 2 ) compared with CeY glass (NL(i) Si and NL(ni) Si % 700 mg/cm 2 ). This differ- ence between the two compositions were already observed and discussed in the first part of this series [26] concerning non-irradiated samples. These are not linked to the irradiation which does not seem to influence notably silicon release.…”

“…The influence of the irradiation on pH was very weak concerning CeY glass with an increased value in the first instants of leaching for both samples. The oxidation of Ce(III) is partly responsible for this increase, through the consumption of H þ ions induced by the reaction already proposed in the first part of this series [26]:…”

“…The synthesis process has been described elsewhere (see Part I of this series [26]). Calculated oxide melts were prepared by weighting corresponding oxides: Al 2 O 3 , SiO 2 , Y 2 O 3 and La 2 O 3 (CeO 2 ).…”

“…This explains thermal properties such as high fusion temperature (T f % 1600°C) and glass transition temperature (T g % 880°C) [8,9,11,[14][15][16]. The chemical durability of LaYSiAlO and CeYSiAlO glasses as a function of pH was studied in the first part of this series [26]. Their particularly good resistance to alteration in neutral and basic media is mainly due to the passivation of the material caused by insoluble elements accumulated at the solution/glass interface [1,2,17,18].…”

“…Their particularly good resistance to alteration in neutral and basic media is mainly due to the passivation of the material caused by insoluble elements accumulated at the solution/glass interface [1,2,17,18]. In the case of CeYSiAlO glass, the likely oxidation of Ce(III) into Ce(IV) has been correlated with an important accumulation of Ce(IV) near the surface (see Part I [26]). Another property that have to be studied to allow long-term predictions is the resistance to irradiation of this family of glass.…”