Application Of Iron Oxide Powder In Lithium-ion And Magnetic Resonance Imaging

Iron oxide powders are widely used in many fields.The two applications of iron oxide powder materials in the field of nuclear magnetic resonance imaging and lithium ion battery are studied in this paper.In the application of lithium ion batteries,as the electrode material,controlling micro-morphology and structure is an effective way to optimize and improve the electrochemical performance of the electrode material.Iron oxide nanomaterials with different morphology and morphology were prepared by sol-gel method,solvent heat method and precipitation method.The product was characterized by X-ray diffraction?XRD?and scanning electron microscope?SEM?.The effects of different experimental conditions and different preparation methods on the morphology and structure of iron oxide nanomaterials were studied.Finally through the blue electric?LAND?battery test system,the electrochemical properties of electrode materials were studied.The main research work of this paper is as follows:?1?The pure phase Fe₃O₄ material was synthesized by solvent thermal method.The effects of reaction temperature and reaction time on morphology and size of Fe3O4 nanoparticles were investigated.The crystal structure and electrochemical properties were tested and analyzed,and the following conclusions were obtained.Reaction temperature is 200°C,heat preservation time is 10h,solvent thermal synthesis of Fe₃O₄ material is pure phase.The sample is a microsphere tightly packed with Fe₃O₄ nanoparticles,and the shape and size are not agglomerated.The diameter of the microspheres is 300⁶00nm.The special appearance of the material can help improve the electrochemical properties of the material to a certain extent.The first discharge ratio was 1172.6mAh/g.After 30 cycles of charging and discharging,the discharge ratio was maintained at 372.3mAh/g.?2?Iron oxide powders with dry gel or aerogel structure were prepared by sol-gel method and atmospheric drying process,then by heat treatment,the?-Fe2O3 anode material was prepared.The effects of preparation technology on morphology and size of?-Fe₂O₃ nanoparticles were investigated,under the condition of different calcination temperature and holding time on anode materials?-Fe₂O₃ performance change rule were studied.Optimization results show that the precursor calcination temperature of 600°C,heat preservation time optimizing 3h,?-Fe2O3 nanoparticles mutual bonding and the product distribution is relatively uniform,disperse uniformity is good.The experimental results show that when the calcination temperature is 600?,holding time to get samples for 3h comprehensive electrochemical properties of the optimal,discharge specific capacity up to 1148mAh/g,for the first time after 30 times recharge cycles,discharge specific capacity stay in a 473mAh/g.?3??-Fe₂O₃/Fe₃O₄ materials were prepared by mechanical mixing.The electrochemical properties of?-Fe₂O₃/Fe₃O₄ materials under different proportions were investigated.Come to the following conclusion:the initial discharge specific capacity and charge specific capacity of?-Fe₂O₃/Fe₃O₄?1:9?were 1128.8mAh/g and800.1mAh/g,respectively,and the coulomb efficiency was 70.9%.When the current density was 50mA/g,the initial capacity of?-Fe₂O₃/Fe₃O₄?1:9?was attenuated,and the specific capacity was maintained at about 849.3 mAh/g.At the current density of100mA/g,the reversible capacity was maintained at about 664.5mAh/g.With the increase of current density,the specific capacity decreased,but the cycle stability was better.In the field of MRI applications,as a new type of magnetic resonance contrast agent,the sensitivity of superparamagnetic iron oxide contrast agent is still insufficient,and cell tracing often requires high concentration of nanoparticles to complete the labeling,which will cause a certain degree of cytotoxicity.If a single cluster of iron oxide nanoparticles can be constructed into a dense cluster structure,it can not only maintain the original superparamagnetic properties,but also its imaging performance can be greatly improved.In this paper,L-ascorbic acid palmitate was used to encapsulate the superparamagnetic iron oxide nanoparticles,and the preparation of the cluster structure was realized by hydrophobic self-assembly.The quality ratio of Vc and SPIO were adjusted?2:1 and 5:1?to construct the Vc-SPIO nano probes.And then magnetic resonance imaging was completed.Mice RAW264.7macrophages were cultured routinely.Using the Vc-SPIO nanometer probe?iron concentration 0²5ug/ml?to complete the cell marking.The cytotoxicity of cell was detected by CCK-8 test.With the molecular ratio of Vc:SPIO was about 2:1,the cells remained normal activity under the concentration of iron in the experiment.However,If the molecular ratio of Vc:SPIO was about 5:1,cell activity was affected with the increase of iron concentration.When iron concentration was greater than 15ug/ml,it exhibited toxicity.Vc-SPIO had no obvious effect on the biological activity of RAW264.7 with the concentration below 15ug/ml.It could be used to label RAW264.7,which lay the foundation for the next animal experiment.