Department of Materials Science EngineeringNanoparticle usually refers to the particle which is ranging from one to one-hundred nm. They have unique properties which can???t be seen in bulk materials; high surface to volume ratio, quantum size effect, surface plasmon resonance and so on. Among nanocrystals, magnetic nanoparticles are hot topics because of their wide usages for application such as catalysis, nano-medicine, electromagnetic wave absorption, bio-sensors and data storage. In the first part of the paper, I briefly introduced overall description of magnetic nanoparticles including magnetism, properties, synthetic method.
Iron cobalt(FeCo) nanoparticles are one of important magnetic nanoparticles because of their large values of permeability and saturation magnetization. So, they can be used in wide range of application. So, there have been many researches to synthesize FeCo nanoparticles. Nevertheless, synthesis of oxygen-free monodisperse FeCo nanoparticles remains challenging. In this paper, the new synthetic method synthesizing of FeCo nanoparticles is introduced. During synthesis, hydrogen gas was directly injected throughout the reaction time, leading to the reduction of oxygen part of the nanoparticles. I also synthesized size and shaped controlled FeCo nanoparticles by controlling the amount and ratio of oleic acid and oleylamine.
I also fabricated magnetic nanoparticles and edge-oxidized graphene (EOG) nanocomposites. Graphene has also attracted considerable attention from a number of different research areas, because it has great potential for a wide usages in application like catalyst, optoelectronic materials, sensors. There are many attempts to fabricate nanoparticles/graphene composites by EDC coupling, in-situ fabrication and so on. In this paper, I synthesized magnetic nanoparticles and EOG composite. EOG has carboxylic acid and hydroxyl functionalities only at the edge of it. So, it has great dispensability on water and better electrical properties than graphene oxide, expecting the superior properties to graphene oxide. I synthesized the composite using two methods; One is EDC coupling and the other is using electrostatic interaction. In second method, the surface of FeCo nanoparticles are exchanged organic ligands into inorganic ligands to give the negative surface charge, while PEI-coated graphene oxide has positive charge. I fabricated FeCo nanoparticles and EOG hybrid materials through electrostatic interaction.ope
