I. Synthesis of magnetic carbon nanoparticles using microwave arcing process and growth mechanism. II. Growth mechanism of vertically aligned carbon nanotubes.

• Main Authors: Liang, Yu-Chia, 梁育嘉
• Other Authors: Hwang, Kuo-Chu
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/53135842543067264895

博士 === 國立清華大學 === 化學系 === 97 === We have demonstrated that the well graphitized core-shell iron/carbon nanoparticles (Fe@CNPs) were produced via an unprecedented "microwave arcing" process from solid metallocene precursors without co-formation of carbon nanotubes. Microwave arcing was generated by microwave absorption of and subsequent discharging between small silicon pieces or short metal wires in a focused microwave oven. Fe@CNPs were well-characterized by various spectroscopic measurements. Saturation magnetization measurement shows that the as-produced core-shell Fe@CNPs are ferromagnetic in nature with a coercivity value of ~ 115 Gauss. The Fe@CNPs were surface functionalized to have either carboxylate or amine functionalities with a water solubility of ~ 500 mg/L and without losing the magnetic properties. The distribution of surface grafted oligomers indicates that the chemical reactivity of the outmost graphene shell is not the same at different locations, with highly strained regions having higher reactivity than less curved regions. Core-shell Ni/ or Co/carbon nanoparticles can also be prepared in a similar way.