Structural characterization of yttrium silica sol-gel microspheres

Sol-gel silica microspheres incorporating yttrium were prepared and structural investigated as possible carrier materials for the radiation inside the cancer tumours. The studied microspheres were obtained by sol-gel and spray-drying methods and thermally treated in order to control the chemical stability of the samples in the human body environment. Several methods were used for structural characterization of the microspheres. The shape and composition of silica microspheres was investigated by Back Scattered Electron Imaging of Scanning Electron Microscope equipped with Energy Dispersive X-ray Analysis (EDXA). Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) was used for the analysis of the distribution of yttrium in the materials. Information about the local structure of the samples was obtained by Nuclear Magnetic Resonance (NMR) Spectroscopy on Si-29 nucleus. The results show that yttrium was well incorporated in some of the silica microspheres and the local structure of the samples is influenced by the incorporation of yttrium into the silica network.