Mesoporous manganese oxide/multiwalled carbon nanotubes as a base material for the 99mTc/99Mo generator: Development, characterization, and implementation study

Abstract

The uptake capacity of Mo on the active MnO2 nanoparticles was determined in a previous study, and it was found to be 7 mg/g. This value is appropriate for 99Mo, which is more complex to separate due to its production using the 235U fission reaction with a high specific activity. Currently, multiwall carbon nanotubes (MWCNTs) linked to mesoporous MnO2 are being prepared and studied as a novel sorbent for the 99Mo produced with a low specific activity by thermal neutron activation of natural molybdenum consisting of 92M0, 94Mo, 95Mo, 96Mo, 97Mo, 98Mo, and 100Mo, based on the 98Mo(n,γ) reaction to prepare the 99Mo/99mTc generator with a high uptake capacity for Mo. FTIR spectroscopy, EDX-mapping, XRD, particle size analysis, FESEM, and TEM analysis were used to characterize the novel mesoporous MnO2/MWCNT sorbent with a large total pore area 193.3 m2/g and porosity about 52%. Several factors influencing the sorption of 99Mo and 99mTc onto the mesoporous MnO2/MWCNTs were studied, including the distribution coefficient (Kd), contact time, temperature, and sorbent/solute ratio, etc. The Mo uptake capacities on the novel sorbent were 133 and 115 mg Mo/g, respectively. A preliminary study on the prepared new sorbent for the 99Mo/99mTc generator was performed, and the elution yield of 99mTc was found to be 82.55% with low 99Mo breakthrough. The radiochemical, radionuclide, and chemical purity of the eluted 99mTc were checked to ensure that it was free of impurities.