Study On Preparation And Performance Of Magnetic Nanocomposites Based On Graphene

With the progress and development of science and technology, all kinds of cultureand Interdisciplinary Communication have been mixed together and deependedgradually. Materials with oneness capability have couldn’t meet the needs of people.Composites have drawn our notices. Composite it’s not the simple sum of the twopure substances. But it has a more extensive and excellent performance on the basis ofthe original performance.With its unique two-dimensional structure of graphene, it has a very prominentperformance in electrical, mechanical, thermal, etc.So it has become one of the focusand hotspot scientists to study. Study on preparation and properties of magneticnanocomposites based on graphene are of great importance. Especially theintroduction of polymer on the basis of magnetic nanocomposites, improves theperformance of the material.The good performance of composites has potentialapplications in the field of electromagnetic shielding, catalyst carrier, capacitors,sensors, biological medicine, environmental protection and so on.Firstly, Graphene （GSN）@Fe₃O₄magnetic nanocomposites were synthesizedthrough modified corecipitated method. Composition and structure analysisdemonstrate that the magnetic nanocomposites were synthesized successfully, and andthe Fe₃O₄obtained is cubic crystal.Morphology analysis indicate that sodium dodecylbenzene sulfonate （SDBS） and graphene make the Fe₃O₄loading on the surface,margin and interlamination uniformly, and the size range is20-50nm. SDBS anionicsurfactant reduces the influence of the interface between grapheme and Fe₃O₄, and isgood for the progress of the performance of composites. Graphene （GSN）@Fe₃O₄magnetic nanocomposites have good superparamagnetism. The saturationmagnetization increases with the increase of the content of Fe₃O₄. Electricalconductivity tests show that the electrical conductivity of the composites increaseswith the increase of the content of graphene. Fe₃O₄makes the stability of thecomposites better than pure graphene.Secondly, in order to improve the conductivity of the graphene@Fe₃O₄magneticnanocomposites, this article also introduced conducting polymers such as polyaniline（PANI）, polypyrrole （PPy）, which makes the electrical conductivity of the composites increase greatly.GNS@Fe₃O₄@PANI ternary nanocomosites were prepared through in situpolymerization method. I changed the inorganic acid which would damage Fe₃O₄, andused p-toluenesulfonic acid （PSTA） as Dopant during the process of experiment,which overcome the defects of dopant caused by corrosion. At the same time, theelectrical conductivity of the composites has been greatly improved. Composition andstructure analysis show that GNS@Fe₃O₄@PANI ternary nanocomosites weresynthesized successfully, and and the Fe₃O₄obtained is cubic crystal. Morphologyanalysis demonstrates that the composites like clusters of coral. Fibrous polyanilinecoated on the surface of Fe₃O₄nanoparticles as well as the surface, layers, edge ofgraphene. Polyaniline has formed dense network, which would link up the surface,layers, edge of the grapheme, and form a conductive path. The PANI also formedconductive network on the surface of Fe₃O₄nanoparticles, which makes theconductivity of the composites greatly increase. The maximum conductivity of theGNS@Fe₃O₄@PANI is14.286S/cm. The GNS@Fe₃O₄@PANI ternarynanocomosites with strong conductivity, magnetic property and good stability havepotential applications in electromagnetic shielding, sensor, capacitors, sewagetreatment. Etc.In addition, this experiment introduced the polypyrrole in order to prepareGNS@Fe₃O₄@PPy ternary composites. I use FeCl3as oxidant, PTSA as the dopingagent to prepare GNS@Fe₃O₄@PPy ternary composites by in-situ polymerizationmethod. Composition and structure analysis indicate that GNS@Fe₃O₄@PANIternary nanocomosites were synthesized successfully, and and the Fe₃O₄obtained iscubic crystal. Morphology analysis show that the composites like clusters ofcauliflower.Spherical PPy coated on the surface of Fe₃O₄nanoparticles as well as thesurface, layers, edge of graphene.PPy has formed dense network, which would linkup the surface, layers, edge of the graphene, and form a conductive path. The PPy alsoformed conductive network on the surface of Fe₃O₄nanoparticles, which enhance theconductivity of the composites. The maximum conductivity of the GNS@Fe₃O₄@PPyis10.253S/cm. The GNS@Fe₃O₄@PPy ternary nanocomosites with strongconductivity, magnetic property have potential applications in electromagnetic shielding, environmental protection, biomedical sciences, sensor, capacitors, andother field of the electronic devices and so on.