A multiparametric study on the behavior of mesoporous silica under electron irradiation

Grafted mesoporous silica is believed to be a candidate for the decontamination of radioactive effluents and the final storage of radionuclides. Under this condition, silica is subjected to continuous electron irradiation due to beta decay of radionuclides. This paper examined two mesoporous silica (SBA-15 and MCM-41) under high-energy electron beam irradiation (0.6 MeV < E < 2.4 MeV). The results showed that the pore structure of both mesoporous silica pellets shrank for all the samples (with 40 % < ΔV_pores < 60 % at 8 × 10¹⁸ e^-/cm²), while no significant damage was observed in the amorphous silica network. The main reason for the structural changes was attributed to electron beam radiation-induced fluidization. Additional experiments conducted with numerous incident electron energies provided more detailed support, confirming that the radiolytic process was the primary cause of fluidization. These findings contribute to a better understanding of electron-irradiation-induced damage and may lead to novel approaches for handling radionuclides with mesoporous materials.