| Magnetic nanoparticles due to the performance of the unique super paramagnetic, the relatively high specific area, low Curie temperature, broadband strong absorption band, recycling, biodegradable and biological compatibility characteristics, and then in magnetic resonance imaging and targeting drug carrier, specific bio separation, magnetic hyperthermia, weight from the adsorption and separation, stealth absorbing wave material, magnetic recording materials, magnetic refrigeration material and its wide application. The morphology and size of the magnetic nanomaterials have great influence on the properties of the particles, and then affect their application field and application effect.Firstly, the ethylene glycol assisted hydrothermal synthesis of octahedral Fe3O4 particles were prepared, by controlling the reaction variables to prepare a different particle size of Fe3O4 particles, and to explore the multiple factors on the preparation of Fe3O4 particle effects, of octahedral Fe3O4 particle formation mechanism of exploration. The morphology and structure of Fe3O4 particles were characterized by SEM, TEM and XRD. The magnetic Fe3O4 particles with different particle sizes can be tested by vibrating sample magnetometer. Magnetic nano composite material was prepared by the combination of Fe3O4 particles and highly conductive graphene sheets. The main contents and results are as follows:1) using ethylene glycol assisted hydrothermal synthesis of octahedral Fe3O4 particles were prepared, and control the reaction of hydrazine hydrate in addition amount of different particle size of octahedral body Fe3O4 particles were prepared, by means of SEM, TEM, XRD and VSM test on the octahedral body Fe3O4 particle morphology, particle size, crystallization and magnetic properties were characterized. Explore the hydrazine hydrate in the preparation of octahedral Fe3O4 particle experiments in the specific role, and hydrazine hydrate play mechanism results show octahedral Fe3O4 magnetic saturation intensity and particle is proportional to the diameter of the and the coercivity increases with the increase of particle size, in 120nm reached maximum particle size further increases, the coercivity decreases.2) using ethylene glycol assisted hydrothermal preparation of octahedral Fe3O4 particles and control reaction in NaOH concentration variable, the preparation of different particle size of eight octahedron Fe3O4 particles were characterized by SEM, TEM, XRD and VSM test means of the octahedral Fe3O4 particle morphology, particle size, crystallization and magnetic properties were characterized to investigate NaOH in the preparation of octahedral Fe3O4 particle experiments in the specific role, and NaOH treatment mechanism of octahedral Fe3O4 magnetic saturation intensity and particle size is proportional to the coercive force with the particle size increased with increasing, the maximum particle size increases, the coercive force decreases.3) to investigate the effect and mechanism of ethylene glycol assisted hydrothermal method in the preparation of eight surface Fe3O4 particles. One "micro reactor" was formed in the precursor solution of ethylene glycol, which limits the particle size, the more the addition of ethylene glycol, the smaller the diameter of the micro reactor, and the smaller the diameter of the particle.4) the TEM, XRD, VSM and Fe3O4 characterization of the super paramagnetic Fe3O4 nanoparticles were prepared by co precipitation method.5) the grapheme sheets were prepared by ultrasonic stripping method, and the Fe3O4 nanoparticles and grapheme sheets were used to prepare the magnetic nano composite materials... |
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