Physical, chemical and radiation shielding properties of metakaolin-based geopolymers containing borosilicate waste glass

Upcycling waste borosilicate glass (BS) is a viable and sustainable way of preserving the natural resources required for the production of new materials and ensuring environmental sanitation and safety. This study was aimed at investigating how the addition of BS influences the physical, chemical, and mechanical properties and shielding performance against neutrons and charged particles on metakaolin-based geopolymer G. Four batches of G infused with 10%, 20%, and 30% wt BS samples and coded as G, G-10BS, G-20BS, and G-30BS, respectively, were fabricated based on the solid-state reaction method. The samples were characterized accordingly using experimental and theoretical procedures. X-ray diffraction analysis of the materials showed that the addition of BS suppressed crystal peaks in the geopolymers. The Vickers hardness values were calculated as 554, 503, 517, and 528 HV under a 0.1 kg load. The values of fast neutron macroscopic cross-section increased from 0.0601 cm−1 to 0.0706 cm−1 as BS content increased from 0 to 30 wt%. The coherent, incoherent, absorption, and total interaction probabilities of thermal neutrons increased in the geopolymer samples. For electrons, the stopping powers
were in the range of 1.575–13.17 cm2/g, 1.571–13.15 cm2/g, 1.571–13.16 cm2/g, and 1.571–13.18 cm2/g for G, G-10BS, G-20BS, and G-30BS, respectively. The projected ranges of carbon ions in G, G-10BS, G-20BS, and G- 30BS are within the limits 0.069–17.87 μm, 0.064–16.99 μm, 0.064–16.99 μm, and 0.057–15.24 μm. The trend of the projected ranges of electrons, protons, α-particles, and C ions with kinetic energies within 15 keV and 15 MeV was mostly in the sequence G > G-10BS > G-20BS > G-30BS. This order was consistent with the density and BS content of the geopolymer samples. The addition of BS to the metakaolin-based geopolymer improved the fast neutron moderating capacity and thermal neutron cross-sections and reduced the range of charged particle radiation in the geopolymers. The neutron shielding ability of G-30BS was found to be better than that of some existing shielding materials. The BS-infused concrete can be useful for the production of concrete used for radiation control.