Wang Qiguan, Moriyama Hiroshi
Research Center for Materials with Integrated Properties, Department of Chemistry, Toho University, Funabashi, Japan.
Langmuir. 2009 Sep 15;25(18):10834-42. doi: 10.1021/la9013762.
A step-by-step method was used to prepare homogeneous ultrathin films composed of [60]-fullerene (C60) and single-walled carbon nanotubes (SWNTs), grafted onto the functional surface of an alkylsilane self-assembled monolayer (SAM) on an ITO substrate with an ITO-C60-SWNT sequence using amine addition across a double bond in C60 followed by amidation coupling with acid-functionalized SWNTs. Atomic force microscope and scanning electron microscope images of the resulting composite film showed two-component ball-tube microstructures with high-density coverage, where C60 was homogeneously distributed in the SWNT forest. The attachment of SWNTs to the residual amine units in the SAM on the ITO substrate (SAM-ITO) as well as on the C60 sphere results in the C60 molecules in the aggregated clusters being more separately dispersed, which forms a densely packed composite film as a result of the pi-pi interaction between the C60 buckyballs and the SWNT walls. It was found using ferrocene as an internal redox probe that the oxidative and reductive processes at the film-solution surface were effectively retarded because of obstruction from the densely packed film and the electronic effect of SWNT and C60. In addition, the electrochemical properties of C60 on SAM-ITO plates observed by cyclic voltammetry were significantly modified by chemical anchorage using SWNTs. X-ray photoelectron spectroscopy (XPS) analysis also indicated the successful grafting of C60 and SWNT. The XPS chemical shift of the binding energy showed the presence of electronic interactions between C60, SWNT, and ITO components. Such a uniformly distributed C60-SWNT film may be useful for future research in electrochemical and photoactive nanodevices.
采用逐步法制备了由[60]-富勒烯（C60）和单壁碳纳米管（SWNTs）组成的均匀超薄膜，该薄膜通过在C60中的双键上加成胺，然后与酸官能化的SWNTs进行酰胺化偶联，以ITO-C60-SWNT的顺序接枝到ITO衬底上烷基硅烷自组装单层（SAM）的功能表面上。所得复合膜的原子力显微镜和扫描电子显微镜图像显示出具有高密度覆盖率的两组分球管微观结构，其中C60均匀分布在SWNT森林中。SWNTs附着在ITO衬底上的SAM（SAM-ITO）以及C60球体中的残留胺单元上，导致聚集簇中的C60分子更分散，由于C60巴基球与SWNT壁之间的π-π相互作用，形成了紧密堆积的复合膜。使用二茂铁作为内部氧化还原探针发现，由于紧密堆积的膜的阻碍以及SWNT和C60的电子效应，膜-溶液表面的氧化和还原过程受到有效抑制。此外，通过循环伏安法观察到的SAM-ITO板上C60的电化学性质通过使用SWNTs的化学锚固得到了显著改变。X射线光电子能谱（XPS）分析也表明C60和SWNT成功接枝。结合能的XPS化学位移表明C60、SWNT和ITO组分之间存在电子相互作用。这种均匀分布的C60-SWNT膜可能对未来电化学和光活性纳米器件的研究有用。
