Synthesis, stability tests and irradiation evaluation of hollow MoS2 nanomaterials
With applications in a new low-activity technetium-99m generator
C.M. van Dijk (TU Delft - Applied Sciences)
R. M. de Kruijff – Mentor (TU Delft - RST/Applied Radiation & Isotopes)
G. Gauri – Graduation committee member (TU Delft - RST/Applied Radiation & Isotopes)
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Abstract
Technetium-99m (99mTc) is a critical isotope in nuclear medicine, used for diagnostic imaging. It is conventionally produced in a aluminum oxide 99Mo/99mTc generator that runs on molybdenum-99 (99Mo) produced by fission of uranium-235. This fission-based production method faces several challenges. To address these challenges, alternative production pathways are being explored. Neutron irradiation of enriched 98Mo nanomaterials and proton bombardement of enriched 100Mo nanomaterials are two of the possible options. Within this research, the pathway of 98Mo neutron capture will be the focus.
Developing a novel circular low specific activity 99Mo/99mTc generator that can run on these materials requires research to be done into the potential materials. The materials must meet two qualifying conditions: they should have a high surface-to-volume ratio, and show high radionuclide extraction potentials. This is an exploratory study to determine if molybdenum disulfides can be synthesized to meet those conditions.
Multiple synthesis methods of MoS2 nanostructures were explored, and insights were given on their morphological and compositional characteristics. Of the six synthesized materials, four were MoS2 nanospheres, one was MoS2 microcubes and one was unable to be characterized
due to unsuccessful separation of the product. Two of the products were further evaluated on their stability and surface area. Stability tests in milliQ were done under two conditions: five consecutive cycle washes and five time-based washing cycles. Both materials exhibited lower Mo breakthrough during the consecutive washes than during the time-based wash cycles. The most compelling results were the downward trend that the Mo breakthrough data shows for the consecutive washes and the high breakthrough percentage in the 24 h soak for one of the samples (namely, 1.2 ± 0.28%) . Furthermore, the same two materials were tested on irradiation performance. Radionuclide extractions were made in milliQ, and extraction yields were calculated for 99Mo.