Preparation Of Conductive Polymer-coated Magnetic Particles Magnetic Liquid

Magnetic liquid has received extensive attention because of its unique features,such as novel movement, low cost, low energy consumption, non-pollution and extensive application scope etc. Magnetic liquid has unique application in the high-fidelity speakers, hermetic sealing, shock absorbers, magnetic sensors and many other fields. To further expand its research applications, this paper has prepared a conductive polymer coated magnetic particles magnetic liquid. Due to the fact that the magnetic particles are coated with a layer of conductive polymer, this kinds of magnetic liquid is expected to control the conductivity of the magnetic liquid when it is applied to the magnetic liquid, conductive organic substance take the sequential order following the magnetic particles to form a conductive organic substance physical arrangement chain.Firstly, this paper prepared the nano-magnetic particles by chemical co-precipitation method in the absence of nitrogen, then Massart magnetic liquid was prepared. After aged for a certain time, nano-magnetic particles were coated with a conductive polymer through the surface in situ synthesis method to obtain a conductive organic compounds modified nano-magnetic particles. The morphology and properties of the Samples were characterized though a variety of test and analysis tools. The specific contents and the results are listed as follows.1. NanoFe3O4 particles were prepared by adopting co-precipitation method and were prepared to Fe3O4 Massart magnetic liquid. Ultimately, polyaniline coated Fe3O4 magnetic liquid was prepared by applying in-situ polymerization method. We analyzed and characterized the samples. XRD, TEM tests showed that the size of Fe3O4 particle is about 10 nm, the size of Polyaniline-coated Fe3O4 particle is about18 nm, the thickness of Polyaniline coating layer is about 4nm and Spherical particles are in good dispersibility. The analysis of FT-TR showed that Fe3O4 particles and polyaniline have a bonding effect to some degree. VSM analysis showed that the saturation magnetization of Fe3O4 particles is 40 emu/g, the saturation magnetization of polyaniline coated Fe3O4 particles is 19 emu/g, which demonstrates that to some extent the magnetic properties of magnetic particles are undermined after magnetic particles were coated with polyaniline.2. Polythiophene coated Fe3O4 particles magnetic liquid and Fe3O4 Massart precursor magnetic liquid were prepared in the first experiment. XRD, TEM tests showed that the size of polythiophene-coated Fe3O4 particle is about 18 nm, the thickness of polythiophene coating layer is about 4nm and spherical particles are in good dispersibility. FT-TR analysis showed that polythiophene and Fe3O4 particles are chemically bonded coating. VSM analysis showed that the saturation magnetization of the Fe3O4 and polythiophene coated Fe3O4 particles are substantially equal.However, if weak remanence and coercivity appear, the magnetic properties are affected after Fe3O4 particles are coated with polythiophene.3. Firstly, cobalt-doped ferrite magnetic ionic liquid was prepared by adopting the massart method. Then, a polythiophene-coated cobalt-doped ferrite magnetic liquid was prepared by applying in situ composites technology. The results of XRD and TEM analysis showed that we have successfully prepared cobalt-doped ferrite,the diameter of the cobalt-doped ferrite particle is about 10 nm, the size of the Polythiophene-coated cobalt-doped ferrite is about 20 nm, the thickness of Polythiophene cladding layer is about 5 nm, TEM observation particles are ball shape,polythiophene cladding layer coating is in uniformity and in good dispersion. FT-TR analysis showed that polythiophene and cobalt-doped ferrite are chemically bonded coating. VSM analysis showed that the saturation magnetization of the polythiophene-coated cobalt-doped ferrite is about 70% of the cobalt-doped ferrite,the saturation magnetization is reduced and meanwhile remanence and coercivity are more obvious after magnetic particles were coated with polythiophene.