Preparation And Study Of Magnetic Nanoparticles And Epoxy Resin Magnetic Nanocomposites

Research on magnetic nanoparticles and magnetic nanocomposites is a hot issuecurrently due to their special performances and extensive applications. However, research onmagnetic nanocomposites is still insufficient and their applications are less mentioned bypeople now. In this paper, the ferrite and epoxy were employed to prepare organic/inorganicnanocomposite magnetic pastes. The modification process of Fe3O4 magnetic nanopowdersand synthesis methods of Ni0.5Zn0.5Fe2O4 magnetic nanopowders were studied, and then theferrite nanopowders were added to epoxy to prepare epoxy resin magnetic nanocompositepastes, whose inorganic nanopowders were uniformly distributed in polymer with a certainviscosity to adapt screen printing process. The dielectric properties and magnetic properties ofthe magnetic nanocomposites were studied. Prospects of applications as dielectric andmagnetic media were preliminary investigated.Magnetic nano-materials and the preparation methods of magnetic nanocomposites aresummarized in this article. Two ferrites of Fe3O4 and Ni0.5Zn0.5Fe2O4 were studied in this work,the modification process and preparation methods of these two magnetic nanopowders wereinvestgated. And epoxy was applied to prepare polyer based magnetic nanocomposites.KH-550,oleic acid,SDS and citric acid were used as modification surfactants to modifyFe3O4 nanopowders. By FT-IR and SEM, the modification effects were analyzed..Ni0.5Zn0.5Fe2O4 nanoparticles were prepared by sol-gel method and chemicalprecipitation method. The results show that nano-size particles can be obtained by bothmethods; the Ni0.5Zn0.5Fe2O4 nanoparticles prepared by sol-gel method are 100-400 nm whichprepared by chemical precipitation method are 50-100 nm. The magnetic of the sampletreated at 700℃for 2h were investigated by vibration sample magnetometer (VSM). Thesaturation magnetization values of the two methods are 79.1emu/g and 70.7emu/g; thecoercivities are almost negligible of 9.2 mT and 7.3 mT. The chemical precipitation methodwas applied to synthesis the magnetic nanoparticles in the experiment.The epoxy resin magnetic nanocomposites were prepared by adding the ferritenanopowders modified with KH-550 to epoxy. The ferrite nanopowders disperse uniformly inthe epoxy resin and have higher permeability with higher concentration of the ferrite nanopowders. However, there is a maximum value of adding different nanopowders. It is 60%(wt. %) of Fe3O4 and it is 75% (wt. %) of Ni0.5Zn0.5Fe2O4.When the concentration excess themaximum value, the paste would have cracks after curing. The dielectric properties andpermeability of the epoxy resin magnetic nanocomposites were measured with Agilentimpedance analyzer. The results show that the dielectric constant of Fe3O4-epoxy compositesis up to 50 with a low loss of about 0.26, but its permeability is only about 1.5. ForNi0.5Zn0.5Fe2O4-epoxy composites, its dielectric constant is 18 with a loss of about 0.45, butthe permeability is up to 3.5, which indicates that it can be used as dielectric and magneticmedia in embedded inductor applications.