Shape-controlled Synthesis And Application Of Nano-iron Oxides With Multiple Morphologies

Different morphology of nanometer?-Fe2O3 were prepared by hydrothermal method and sol-gel method;nanometer Fe3O4 was prepared by solvent thermal method,in which ferric nitrate,urea,citric acid were used as the main raw material.Nanometer?-Fe2O3 was prepared by sol-gel method,and the phase structure,particle size,morphology characterization were analyzed.The results show that the nano?-Fe2O3 is spherical,the particle size is about 40nm,but the agglomeration between the particles is serious.By magnetic analysis,the nano?-Fe2O3 is soft magnetic material.Its coercivity and remanence is close to 0,which shows some paramagnetic.Nanometer?-Fe2O3 was prepared by hydrothermal method.The effects of preparation conditions?including the reactant ratio,reaction time,reaction temperature,calcination temperature?on nanomaterial phase structure,particle size and morphology were researched and discussed.The key process conditions of preparing nanometer iron oxide materials with excellent performance were gotten.?1?Reaction conditions:reactant ratio is 1:3,reaction temperature is 180?,reaction time is 6 hours.The nanometer?-Fe₂O₃ particles are uniform distribution and better dispersion,it is hexahedron and mixed some eight surface structure.?2?The nanometer?-Fe₂O₃ obtained at optimal conditions was calcined at 450?.The products before and after calcinated are?-Fe2O3.There has little difference in the morphology,size and structure.?3?The magnetism of samples before and after calcinated is analyzed.They are both soft magnetic material.The coercivity and remanence is approach to the 0 and it has a certain paramagnetic properties.It is feasible that nano?-Fe2O3 was prepared by hydrothermal method without the high temperature calcination,and little effect on the magnetic properties of the samples,Hydrothermal synthesis without the high temperature calcination can simplify the process and save energy.On the basis of the above studies,the effects of surfactant and dispersing agent during the reaction have been researched respectively.Adding different surfactants can get different morphology of nanometer?-Fe2O3.The sample morphology is hexahedron while adding PVP,the sample morphology is sheet-shaped while adding SDBS.The morphology is different while adding different amounts of surfactant.With the added amount increasing,the morphology of?-Fe2O3 is gradually changed from the hexahedron to spindle,and then from the spindle to spherical.When ethylene glycol is used as a dispersing agent,with ethylene glycol content increasing gradually,the morphology of the product is changed from the hexahedron to the spindle shape,then from the spindle to spherical.The different amount of dispersing agent can change the morphology of product.The magnetic properties of samples were measured by vibrating sample magnetometer?VSM?.The different kinds of surfactant have large effect on the magnetic properties.The amount of surfactant and glycol dosage has a little effect on the magnetic.Nanometer Fe₃O₄ was prepared by solvent thermal method.The ethylene glycol completely replaced the water as solvent,and the ethylene glycol is reducing agent too.The shape of nanometer Fe₃O₄ is spherical,and its particle size is uniform,its dispersion is good.The nanometer material has the soft magnetic structure.Its coercivity and remanence are approach to the 0.It is superparamagnetic.The ink is obtained by the nano?-Fe₂O₃ and Fe₃O₄ with a certain formula.The fineness of the tow ink is about 1?m which detected by scrape fineness gauge.The viscosity of them are relatively 90 and 93pa/s.The ink was detected by the VSM,the ink has a certain magnetic with the saturation magnetmeter is about 3800Oe.