Influence of gamma ray irradiation on metakaolin based sodium geopolymer

A multinuclear static NMR study of geopolymerisation

“…Indeed, for the last decades, aluminosilicate materials, also known as geopolymers [9], have been largely studied due to their promising potential applications as environmentally friendly alternatives to Portland cement [10][11][12][13]. The interest they could provide for waste remediation and in particular nuclear waste or heavy metals containment have also motivated intensive research on this field since the last 20 years [14,15]. These amorphous aluminosilicate materials are typically synthesised under highly alkaline conditions from a solid aluminosilicate such as fly ash, slag or some calcined clay such as metakaolin (MK).…”

Effects of gamma-ray irradiation on leaching of simulated 133 Cs + radionuclides from geopolymer wasteforms

“…Thus it appears that the gamma rays did not produce significant changes in the wasteform morphology; i.e., no deformation, damage, or cracking. Usually, low-and intermediate-level radioactive nuclides emitting gamma rays induce structural changes and/or damage in solid materials [27,32].…”

“…S3) reveal a slight shift in the Al-O-Si stretching vibration from 447.8 cm À1 to 454.2 cm À1 after irradiation. This could lead to a relaxation of the microstructure at the oxygenlinked Si-Al tetrahedral coordination [27,34,36].…”

“…The porosities of the non-irradiated and irradiated samples, as determined by the MIP tests, were 11.6% and 12.9%, respectively. Lambertin et al [27] found that gamma rays could change the pore structure of metakaolin-based geopolymers. This might be attributed to the radiolysis of water, reorganization of the thin pore wall, and a decrease in the average Si-O-Al bridging-bond angle.…”

“…Because the gamma rays changed the microstructure of the geopolymers [27], it was likely that gamma rays from radioactive cesium would degrade radioactive waste immobilization in geopolymers.…”