X-ray protection, surface chemistry and rheology of ball-milled submicron Gd2O3 aqueous suspension
School of Engineering
X-ray protective garments are typically comprised of lead-based materials, which are toxic to both people and the environment. Developing alternative lightweight radiation shielding materials is a priority for protecting people working with radiation. Gadolinium, with an electron configuration typical of radiation shielding elements, is proposed as a non-toxic replacement for lead. This study provides new insights into the potential for a gadolinium suspension for replacing lead and proposes an inexpensive and effective preparation method. Submicron gadolinium oxide (Gd2O3) was generated using a cost effective ball milling method involving addition of NaCl. Then, the dispersed-flocculated behaviour of Gd2O3 aqueous slurries was studied via yield stress and zeta potential techniques to stabilise the dispersion. The relationship of the transmission-volume fraction at different kVp from an interventional radiology source was established to investigate radiation attenuation performance of the suspension. At a low volume fraction (0.082), the gadolinium slurry attenuated more than 95% of the X-ray load from a 50⬜100 kVp source. The equivalent weight-thickness at the same attenuation of 95% (5% transmission) of the Gd2O3 suspension was 1.5 g/cm2, which is comparable to that of equivalent commercial lead-based materials (>1 g/cm2). This research is significant for developing a non-lead-based material, Gd2O3 suspension, which offers effective radiation attenuation with weight-thickness minimisation and safe use and disposal.