Příprava vybraných nanokrystalických oxidů lanthanidů a jejich akutní akvatická toxicita pro sladkovodní zelené řasy

Abstract

The diploma thesis describes the preparation of lanthanides oxides nanocystallites (Gd2O3, Sm2O3, Er2O3) via thermal decomposition of a complex formed by the default lanthanide salt and glycine. Decomposition of the complex was observed at temperatures about (250 ± 10) °C. Ultra-fine powder of the lanthanides oxide nanocrystallites was obtained via this method. The resulting nanocrystallites were characterized by X-ray powder diffraction analysis, which revealed the size of the gadolinium oxide nanocrystallites 10 nm, the samarium oxide nanocrystallites 11 nm and the erbium oxide nanocrystallites 10 nm. Morphology of the samarium oxide nanocrystallites was examined by scanning electron microscopy and transmission electron microscopy. Electron diffraction observed in transmission electron microscopy corresponds to the results obtained from X-ray powder analysis. The elemental composition of the products was confirmed by EDS analysis. Further, the particle size was determined (in this case the agglomerated nanocrystals) by particle size distribution analyzer. At least, acute aquatic toxicity of prepared nanocystallites of lanthanides oxides was tested, when freshwater green algae Desmodesmus subspicatus and Raphidocelis subcapitata were used as a detection organism.