I. 微波電弧法製備磁性奈米碳球及其生長機制 II. 垂直奈米碳管生長機制之研究

我們可以利用固態有機金屬的前驅物，經由一個從未報導過的" 微波電漿" 法製備出良好石墨層包覆的金屬碳奈米顆粒，並且沒有碳管副產物的出現。微波電漿的產生可藉由在聚焦式微波爐中，矽碎片或金屬絲的吸收微波。石墨層包覆的鐵奈米顆粒的特徵性質可由不同的光譜所測量而得。石墨層包覆的鐵奈米顆粒的順磁性可由超導量子干涉儀所測得，並顯示有大約115 高斯的矯頑力。我們可以進一步將這些磁性奈米顆粒進行表面官能基化，使其帶上酸根或胺根，其水中溶解度可達每升五百毫克，並且在水中不失去其磁性。我們從電子顯微鏡中得知，這些磁性奈米顆粒表面上寡聚合物的分佈並不均勻，而是應力較大的區域比較平緩的區域會有較多的接枝。除了鐵以外，鎳和鈷金屬亦可由類似的方是被包覆在石墨層中。

關鍵字

奈米碳球；奈米碳管；異原子摻雜

並列摘要

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.

並列關鍵字

in situ ； carbon nanotubes ； carbon nanoparticles

參考文獻

[1] S. Iijima, Nature 1991, 354, 56-58.

[2] S. Iijima, T. Ichihashi, Nature 1993, 363, 603-605.

Amaratunga, Carbon 2004, 42, 95-99.

[7] J. Y. Miao, D.W. Hwang, K. V. Narasimhulu, P. I. Lin, Y. T. Chen, S. H. Lin, L. P. Hwang, Carbon 2004, 42, 813-822.

[13] V. P. Dravid, J. J. Host, M. H. Teng, B. Elliott, J. Hwang, D. L. Johnson, T. O. Mason, J. R. Weertman, Nature 1995, 374, 602.

國際替代計量

I. 微波電弧法製備磁性奈米碳球及其生長機制 II. 垂直奈米碳管生長機制之研究

主題瀏覽