Ionic Liquids Assisted Synthesis Of Magnetic Materials And Their Related Performance Research

In this paper, Fe3O4nanoparticles and Ni/Fe3O4nanoparticles were successfully synthesized by using ionic liquid of1-Butyl-3-methylimidazolium tetrafluoroborate ([BMIN]BF4) instead of traditional surfactants as templates. The structure, morphology and properties of as-prepared products were characterized by XRD, Raman, FT-IR, SEM, TEM, VSM, et al.First, Well-dispersed Fe3O4nanoparticles have been successfully synthesized via [BMIN]BF4-assisted co-precipitation process at70℃. On the basis of experiments with different amount of [BMIN]BF4ionic liquids, the influence of crystal structure, morphology and properties of the sample have been investigated. Then, the mechanism of the ionic liquid [BMIN]BF4in the reaction also has been discussed. The results show that a small amount of ionic liquid [BMIN]BF4is contribution to the dispersion of Fe3O4nanoparticles while too much ionic liquid [BMIN]BF4go against the dispersion due to the formation of mesh structure between the different [BMIN]BF4. When the doping amount of the ionic liquid for3～5mL, Fe3O4nanoparticles are in good dispersion. The diameter of these Fe3O4nanoparticles is about15nm and the Saturated magnetic intensity (Ms) is63.8emu·g-1.Then, we further use [BMIN]BF4-assisted two-step method to prepare nickel nanoparticles and Ni/Fe3O4core-shell nanoparticles. Then, the synthesis mechanism of Ni/Fe3O4core-shell nanoparticles also has been discussed. The results show that nickel nanoparticles synthesized are amorphous structure, the diameter of these nickel nanoparticles is about30～50nm and the Saturated magnetic intensity (Ms) is37.2emu·g-1. On the other hand, Ni/Fe3O4nanoparticles synthesized nanoparticles can prove with core-shell structure by instrumental analysis, the diameter of these Ni nanoparticles is about200～300nm and the Saturated magnetic intensity (Ms) is53emu·g-1.