Preparation And Characterization Of Nickel Ferrite And Poly-furfural/Nickel Ferrite （PF/NiFe₂O₄） Magnetic Composite Nanomaterials

Spinel type ferrite has the well chemical durability, thermostability, magneticproperty and electrical property. Therefore it has been widely used in microwavedevices, sensors, catalytic and magnetic material. In recent years, magnetic materialsare also used in medicine and health care and show very good prospects. But becauseof its very high magnetism, the agglomeration naturally occurs and seriously affectsits performance. Combining magnetic inorganic and organic components can solvethe agglomeration and improve its magnetic performance and expand the usable fields.Among many polymers, poly-furfural (PF), a conductive polymer, is used to preparethe inorganic-organic composite magnetic material. But those traditional methods ofpreparing this kind of composite material can not avoid free polymerization ofmonomer molecules in the solution and does not ensure well-distributed property ofthe as-prepared materials. In this paper, traditional two-steps method is improved andused to prepare a series of poly-furfural/nickel ferrite (PF/NiFe2O4) compositemagnetic nanomaterials. And their magnetic property is investigated. It is differentfrom previous in-situ polymerization method that in the improved two-step method,in-situ polymerization of monomer molecules, second step of two-step method, reallybecomes true on the surface of the magnetic material by the process of ultrasonicdispersion-adsorption-in situ catalytic polymerization and really avoids freepolymerization of monomer molecules in the solution.This thesis mainly has the following two aspects:1. Sol-gel method is used to prepare NiFe2O4.magnetic material and pH valueand calcination temperature are investigated to obtain good magnetic performance ofNiFe2O4material. TEM, XRD and VSM technologies are used to characterize theas-prepared materials. Results show that magnetic property of obtained NiFe2O4isrelative good when pH value is7.45and the calcination temperature is800℃.2. by using improved two-step method, a series of PF/NiFe2O4compositemagnetic nanomaterials are prepared and characterized by using TEM, XRD andVSM, IR, TG-DTA technologies. The results show that the property of theas-prepared PF/NiFe2O4composite magnetic nanomaterials regularly changes and thesize decreases.