Boron assisted low temperature immobilization of iodine adsorbed by silver-coated silica gel

To immobilize the radioactive iodine isotopes, a series of borosilver silica gel glasses with iodine loaded in silver-coated silica gel ranging from 20 to 30 wt% (I− content in each sample was 8 wt%) had been successfully immobilized by muffle furnace from 450 °C to 550 °C for 6 h. With the increase of I− in silver-coated silica gel, optimum sintering temperatures corresponding to the maximum amorphous fraction in each system decreased from 550 °C (0.98) to 490 °C (0.68) and finally to 460 °C (0.66). The IR spectrums results show that the vitrified matrix is mainly consisted of [BO3] and [SiO4]. The SEM-EDS patterns show that iodine is uniformly distributed in the sample loaded with 20 wt% of iodine in silver-coated silica gel. In addition, the specimen shows lower porosity with higher amorphous fraction. Our findings demonstrate the potential of boron for the immobilization of silver-coated silica gel with different radioactive iodine loadings.