Preparation And Characterization Of Core-Shell Bi-Functional Microspheres With Magnetism And Fluorescence

As the tool of diagnoses,operation and conveyance of medicament,magnetic and fluorescent compound provided a new method and opportunity for chemistry,biology and medicine.In this dissertation,using the Fe₃O₄ as magnetic core and rare earth luminescent materials as shell,the core-shell structrual microspheres were prepared,and the preparation method and the properties of the magnetic and fluorescent compound were discussed.The main content is as follows:Fe₃O₄ particulates with well monodisperse and high magnetic saturation have been synthesized by solvothermal method.In the experiments,the influences of the reaction temperature,reaction time,precursor concentration and surfactant on the products were discussed.The microspheres with core-shell structure(denoted as Fe₃O₄@SiO₂) have been prepared through a modified St(o|¨)ber method.Some factors that would affect the sizes and the morphologies of the paticles were discussed,such as precursor concentration,volume of the hydrolyzing medium,concentration of TEOS and the dense ammonia.Core-shell structural Fe₃O₄@Y₂O₃:Ln³⁺(Ln=Eu,Tb) magnetic and fluorescent bi-functional microspheres have been synthesized.This compound microspheres pocessed the characteristic luminescence of rare earth ions and superparamagnetism of magnetic materials. The forming procedure were discussed also.The magnetic and fluorescent bi-functional compound microspheres with core-shell structure of Fe₃O₄@SiO₂@Eu(DBM)₃·2H₂O/SiO₂ with red light and Fe₃O₄@ SiO₂@ SiO₂-Tb(PABA)₃ with green light were prepared through two different methods.The results showed that the SiO₂ doped rare earth complexs were coated on the surface of the magnetic core,and the core-shell materials possessed high magnetic saturation and fluorescent properties.