Preparation And Electromagnetic Properties Of The Ferrite-carbon Nanotubes/conductive-polymer Ternary Composites

With the development of human civilization process, single material has not meet the demands in today’s engineering. Multifunctional composites, combining with the advantages of a variety of materials and overcoming the defects of single material, have great advantages in engineering applications. In this paper, for the conductive-magnetic materials, we combine inorganic-magnetic material with organic-conductive polymer via composite method in order to prepare the electromagnetic composites. The structures and morphology of samples have been characterized by FTIR, XRD, SEM and TEM. The conductive property of sample has been tested by a four-probe resistivity instrument at room temperature. A Lakeshore 7404 VSM is used to measure the magnetization of samples. And the synthetic and magnetic mechanism have been studied. The mainly research work is as follows:(1) In the second chapter, the results of FTIR, XRD, SEM and TEM indicate that the Ferrite-filled MWCNTs and the chitosan-decorated ferrite-filled MWCNTs/polythiophene composites have been prepared successfully, respectively.There are some interactions among the components of the chitosan-decorated ferrite-filled MWCNTs/polythiophene composites. VSM illustrates that the chitosan-decorated ferrite-filled MWCNTs/polythiophene composites exhibit hysteresis loop begaviour, with saturation magnetization(Ms = 0.18 emu/g) and coercivity(Hc = 312.5 Oe). The four-probe conductivity measurement suggests that the conductivity of the composites reaches 1.613 S/cm.(2) In the third chapter, the results of XRD and FTIR show that there exists some interactions among the components of the BaFe12O19/MCNTs/P(3MT)composites. SEM and TEM images indicate that MCNTs are adsorbed onto the surface of BaFe12O19 particles, and the BaFe12O19/MCNTs powders are coated by P(3MT). P(3MT) and MCNTs have been used to adjust the conductivity. The magnetic parameters such as Ms and Mr of the BaFe12O19/MCNTs/P(3MT)composites depend on the Ba Fe12O19 content. When the mass ratio of BaFe12O19 to MCNTs is 0.4, and the mass ratio of BaFe12O19/MCNTs to P(3MT) is 0.15, the conductivity, Ms and Mr of the BaFe12O19/MCNTs/P(3MT) composites possess thebest conductivity and stronger hysteretic loss ability.(3) In the fourth chapter, the results of FTIR and XRD show that there exists some interactions among Mn0.6Zn0.4Fe2O4, CNTs and PANI. SEM and TEM images indicate that Mn0.6Zn0.4Fe2O4 is formed onto the surface of the CNTs, and PANI nanolayers are coated onto the surface of Mn0.6Zn0.4Fe2O4 and CNTs. Conductivity tests illustrate that the composite has the performance of semiconductor. The results of VSM indicate that the composite exhibits a clear hysteretic behavior. When the value of m(Mn0.6Zn0.4Fe2O4-CNTs)/m(An) is at 0.15, the Mn0.6Zn0.4Fe2O4-CNTs/PANI nanocomposites possess the best magnetic parameter and the strongest hysteretic loss ability.(4) In the fifth chapter, the results of FTIR and XRD patterns reveal that there are interactions among graphene-CNT, CoFe2O4 and polyaniline. SEM and TEM images clearly show that reticular branch structures of the composites. In the composites, CoFe2O4 is dispersed onto the surface of the graphene-CNT. And polyaniline is coated on the surface of graphene-CNT and CoFe2O4. The results of VSM indicate that the composite exhibits a clear hysteretic behaviour. Conductivity tests illustrate that the composite has the performance of semiconductor. When the mass ratio of the graphene-CNT/CoFe2O4 to aniline is 1:3, the saturation magnetization of the graphene-CNT/CoFe2O4/polyaniline composite reaches 39.6emu/g, the residual magnetization achieves 20.1 emu/g and the conductivity reaches 1.957 S/cm.