Preparation Of High Magnetic Conductive Composites

As the important industry materials, inorganic/organic hybrid nanomerials have been widely used in various important fields, such as drug targeted delivering, biosensor, water purification, cell separation and so on. The present work reports on the synthesis of four kinds of complex functional materials with novel routes. Effects of structures and shapes of these samples on the characters, such as magnetic and electrical properties are investigated. The formation mechanisms of these products are proposed. The main works are listed as the following:A facile and novel method for preparing Fe3O4/Polypyrrole (PPy) nanofluids was presented, in which one-pot route was used. FeCl3·6H2O was used as the iron source and the oxidizing agent to produce PPy. Trisodium citrate (Na3cit) was used as the reducing reagent. This nanofluid can keep long-term stability and very good dispersing. Fe3O4/PPy nanoparticles (NPs) can still keep dispersing well after the nanofluid has been standing for one months and no sedimentation is found. Fe3+ions remained in the solution adsorbed on the surface of the Fe3O4NPs. The polymerization reaction of the pyrrole monomers took place with these Fe3+ions as the initiator. The particle size of the as-prepared Fe3O4/PPy can be easily controlled from7to30nm by adjusting the amount of pyrrole monomer. The steric stabilization effect was used to explain the stability of the nanofluids, in which PPy took key action. The as-prepared Fe3O4/PPy NPs exhibit superparamagnetic behavior.Core-shell structured Ag/PPy nano-particles (NPs) were prepared by a facile method through the redox reaction of silver nitrate and pyrrole in the presence of sodium dodecyl benzyl sulfonate (SDBS), where the SDBS was used as the template to induce the formation of nanofiber-like Ag/PPy core-shell structure. The formation processes of this kind of structure were proposed. Firstly, sphere-like Ag/PPy structures were produced. Secondly, these sphere-like particles assembled to form nanofiber-like morphology. The effects of the concentration of the SDBS on morphology of the sample were investigated. When the morphology of the samples changed from spherical to nanofibrous, the electrical conductivity increased from11±2to165±5S/cm.Core-shell structure of Fe3O4/Ag/Polypyrrole (PPy) NPs (NPs) was prepared by a facile method through the redox reaction of silver nitrate and pyrrole in the presence of polyvinyl pyrrolidone (PVP) as protection agent. The presence of PVP has effect on the morphology and structure of the as-prepared Fe3O4/Ag/PPy NPs. Rod-shaped Fe3O4/Ag/PPy NPs were obtained with the increase of the concentration to0.125mM, in which the wirelike core was formed by the aggregation of Fe3O4and Ag nanoparticles. At the same time, the PPy shell of the as-prepared NPs became uniform and thicker with the increase of the concentration of PVP in the solution. The concentration of AgNO3solution affects the morphology and structure of the as-prepared Fe3O4/Ag/PPy NPs. The PPy shell of the as-prepared NPs became uniform and thicker with the increase of the concentration of AgNO3in the solution. The electronic conductivity of the as-prepared NPs can be adjusted from337to30S/cm by changing the thickness of the PPy shell. All the as-prepared NPs in the present work exhibit superparamagnetic behavior.A facile and efficient one-pot solvothermal synthetic route is proposed to fabricate spherical La3+doped zinc ferrite clusters without any template and surfactant. Numerous nanoparticles are aggregated to form clusters with uniform shape and size. Different values of x in ZnLaxFe2-xO4induce different magnetic parameters for these clusters. Especially, the maximum of the saturation magnetization of ZnLaxFe2-xO4clusters is86emu/g when x=0.02. This result is different to those reported, in which the saturation magnetization decreased with La3+doping. The as-prepared clusters also showed good performance in removal of pollutants like methyl orange from water by adsorption. Different Brunauer-Emmett-Teller (BET) surface areas may induce a different capacity in removal of the pollutant. Use a simple surfactant CTAB to control the shape of the ZnLao.o2Fe1.98O4ferrite. And as the changing of the shape, the magnetic of the materials changed a lot. At the same time, we made PPy coating ZnLao.02Fe1.98O4, and we succeed produced ZnLao.02Fe1.98O4/PPy complex materials. It conductivity is169S/cm and it has an enhancement on the capacity in removal of the pollutant.