Preparation and colloidal behaviour of surface-modified EuF_3

摘要

Surface-modified EuF_3 nanoparticles has been produced by mixing of NaF and Eu(NO_3)_3 aqueous solutions in the presence of sodium citrate as stabilizer. Transmission electron microscopy and dynamic light scattering has shown citric ions influence on the particle size and morphology. Modified and unmodified EuF_3 samples were characterized by X-ray diffraction, elemental analysis, IR and luminescence spectroscopy. The results indicate that citrate ions bond chemically with EuF_3 particle, forming a layer onto the surface. The layer stabilizes nanoparticle colloids and prevents their aggregation. In the case of modified EuF_3 colloids, reversible precipitation-peptization processes at varying pH values and Cu~(2+) chemosorption by citric layer are revealed.