Synthesis of fullerene encased single-walled carbon nanotube by means of electro-chemistry

采用电化学方法，以高氯酸锂的DMF溶液为电解液，在C60的甲苯溶液中对单壁碳纳米管进行了富勒烯的掺杂。ca的还原电压施加-0.5V的C_<60>富勒烯以将富勒烯分子掺杂到单壁碳纳米管垫上，所述单壁碳纳米管垫附着在Pt板电极的两端。结果表明，碳纳米管完全包覆在正极表面<60>。另一方面，负极上的SWNT垫很少包裹富勒烯;大多数富勒烯在管的外部，Li附着在表面上。这些事实表明，由于静电力的作用，C_的阴离子<60>接近正极，并被有效地包裹在单壁碳纳米管中。利用<60>拉曼散射光谱对碳分子在碳纳米管空间中的热聚合进行了详细的研究，以阐明碳分子由阵列结构向管状结构的聚合过程<60>。结果，在宿主管内形成0.7nm直径的管，并且管的直径改变为大直径，以使管壁间分离与货车范德华距离相匹配。提出了一种基于（9，0）字形管成形的内管直径变换模型。本课题还对双壁碳纳米管进行了溴掺杂实验，发现电子可以从外管转移到溴分子上，但不能从内管转移到溴分子上。这一事实也得到了基于自洽紧密约束模型计算的理论论证的支持，该模型计算是与宾夕法尼亚州立大学的小组合作进行的。

By using the electro-chemistry method, doping of Fullerenes within the single-wall carbon nanotube (SWNT) was carried out from the toluene solution of C60 with electrolyte of lithium-perchiorate in DMF. Reduction voltage of ca. -0.5 V for C_<60> fullerene was applied in order to dope the fullerene molecules to SWNT mats, which were attached on the both ends of the Pt-plate electrodes. As results, SWNT mat attached on the positive electrode fully encases the C_<60> molecules. On the other hand, SWNT mat on the negative electrode rarely encases the fullerene ; most of the fullerenes were on the outside of the tube and Li was attached on the surface. These facts suggest that the anion of C_<60> was approached to the positive electrode due to electrostatic force and was efficiently encased within the SWNT. Thermal polymerization of C_<60> molecules, which is progressed in the nanotube space, was investigated detailedly by using Raman scattering spectroscopy in order to clarify the polymerization process from the array structure of C_<60> molecules to the tubular structure. As a result, 0.7 nm diameter tubes were formed inside the host tube and the diameter of the tube was changed to large diameters in order to match the inter-tube-wall separation with the van der Waals distance. We proposed a diameter transformation model for the inner tubes, which is based on forming the (9,0) zig-zag tube at first. Experiments of bromine doping to the double-wall carbon nanotubes were also carried out in the present program, and we found that the electrons can be transferred to the bromine molecules from the outer tubes, but they cannot be transferred from the inner tubes. This fact was also supported by the theoretical arguments based on the self-consistent tight, binding model calculation, which was carried out as the collaboration work with the group at Pennsylvania State University.