Preparation And Property Research Of Fe₃O₄/polymer Nanocomposites

Various functional groups can be introduced on the surface of magnetic-polymer composites, which makes magnetic-polymer composites easily be separated or orientated under the magnetic field; and shows practical applications in many fields including magnetic materials, biomedicines and separation engineering, et al. The goal of the thesis is to explore the synthesis methods of novel Fe₃O₄/Polymer nanocomposites, to reseach on their optical, electronic, magnetic properties. It establishes the foundation for developing the application of Functionlized Fe₃O₄/Polymer nanocomposites. The main results are summarized as follows:1. Fe₃O₄/Polystyrene (PS) nanocomposites have been successfully fabricated via an O/W microemulsion route. The formation of Fe₃O₄/Polystyrene nanocomposites is confirmed by XRD and IR spectrum. Researches from optical properties showed that, compared with the pure PS, the absorption peak of the nanocomposites red shifted 100nm in the UV-Vis spectrum; and the peak intensity of the nanocomposites in the PL spectrum decreased and one new peak appeared. Also, the nanocomposites owned good magnetic property.2. Fe₃O₄/PS nanocomposites have been successfully synthesized in cyclohexane via an ultrasound-assisted route. XRD and IR Spectrum of the final product showed the formation of Fe₃O₄/PS nanocomposites. The UV-Vis absorption and PL spectra of Fe₃O₄/PS nanocomposites obviously differed from those of the pure PS due to the presence of Fe₃O₄ nanoparticles. The electrochemical researches of composites at room temperature showed that Fe₃O₄/PS nanocomposites owned stronger ability to promote electron transfers between catechol and the Au electrode than Fe₃O₄ nanoparticles prepared under the same conditions.3. Fe₃O₄/Polyacylamide (PAM) nanocomposites have been successfully synthesized via an ultrasound-assisted route. XRD proved that the formation of Fe₃O₄/PAM nanocomposites. The electrochemical researches of composites at room temperature showed that the electron transfer ability between catechol and the Au electrode reduced with the increase of the content of PAM. UV-Vis absorption spectra of composites showed a strong absorption in the range from 210-600nm, and the absorption peak slightly blue-shifted with the increase of content of PAM.4. Wrapped CuS nanowires have been successfully prepared via a simple hydrothermal reaction. SAED pattern showed that the wrapped CuS nanowires were polycrystalline, which was comprised of small nanoparticles. TEM observations showed that wrapped nanowires could grow and further transfer to hollow spheres with the prolonging of the reaction time from 2h to 13. UV-Vis spectra of CuS prepared at 180℃for different time were studied. The possible transfer mechanism from wrapped nanowires to hollow spheres was suggested.