Preparation And Characterization Of Rare Earth Compounds Nanofibers Via An Electrospinning Technique

As a member of nanomaterials, nanofiber has become a hot studied subject in the field of nano-technology due to its superior optical, acoustic, electrical, magnetic, thermal and mechanical properties. Rare-earth oxide, doped rare-earth oxide and rare-earth perovskite composite oxide are used in many high-tech fields. Preparation, properties and applications of these compounds have become an important research field.In this dissertation, sol-gel method was applied to prepare the precursor solution with a viscosity and electrospinning technique was used to fabricate PVP/Ce(NO₃)₃, PVP/[Y(NO₃)₃+Eu(NO₃)₃], PVP/[La(NO₃)₃+Fe(NO₃)₃] and PVP/[La(NO₃)₃+Co(CH₃COO)₂] composite microfibers. CeO₂, Y₂O₃:Eu³⁺, LaFeO₃ and LaCoO₃ nanofibers were obtained by calcinations of the above composite microfibers.The morphology of fibers were discussed by adjusting all the important parameters such as concentration of PVP, voltage, distance between tip and collector, the mass of metallic salts added to the sol. As a result, 46wt% is the best PVP concentration. With the increasing in the concentration of PVP, the diameter of composite fibers increased and the morphology changed from nonuniformity containing beads to regularity and then uniformity; 18kV is the best voltage. With the increasing of the voltage, the diameter of composite fibers first decreased and then increased, and the ratio value of long axis to short axis increased and then decreased; 20cm is the best distance between tip and collector. Increasing in the distance, the electrostatic field intensity was decreased and the diameter of the fibers increased and become uniform; 10wt% is the best metallic salts concentration. The addition of metallic salts added to the sol strengthened the electrostatic field intensity and made the diameter of composite fibers decrease. The metallic salts increased the surface tension and resulted in the appearance of beads.The samples were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TG-DTA), Fourier transform infrared spectra (FTIR) and so on. All the results show...