Hayashi Takuya, Shimamoto Daisuke, Kim Yoong Ahm, Muramatsu Hiroyuki, Okino Fujio, Touhara Hidekazu, Shimada Takashi, Miyauchi Yuhei, Maruyama Shigeo, Terrones Mauricio, Dresselhaus Mildred S, Endo Morinobu
Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano-shi 380-8553, Japan.
ACS Nano. 2008 Mar;2(3):485-8. doi: 10.1021/nn700391w.
We found that by fluorination of double-walled carbon nanotubes (DWNTs), it is possible to suppress only the Raman radial breathing mode and absorption peaks from the outer (large diameter) tubes of DWNTs. In contrast, Raman signals from the inner shells showed no difference from the pristine DWNTs. The stability of the inner shells of fluorinated DWNTs was also confirmed from the photoluminescence (PL) map and the optical absorption spectra, which only showed the signals from the inner shells of DWNTs, with no distinct change in the optical properties of the inner tubes after fluorination. Our results indicate that once fluorinated, there exists only a weak, if not none, interaction between the inner tube and the outer fluorinated tube, proving that fluorination can be used to suppress the optical properties of carbon nanotubes without interfering the properties of inner tubes. The present finding can be important in electronic and sensor applications, keeping the inner tube from having unwanted contact with other substances that may distract from the inner tube's own characteristics.
我们发现，通过对双壁碳纳米管（DWNTs）进行氟化处理，仅抑制DWNTs外（大直径）管的拉曼径向呼吸模式和吸收峰是可能的。相比之下，内壳层的拉曼信号与原始DWNTs没有差异。氟化DWNTs内壳层的稳定性也通过光致发光（PL）图谱和光吸收光谱得到证实，这些图谱和光谱仅显示了DWNTs内壳层的信号，氟化后内管的光学性质没有明显变化。我们的结果表明，一旦氟化，内管与外氟化管之间即使存在相互作用也是微弱的，这证明氟化可用于抑制碳纳米管的光学性质而不干扰内管的性质。这一发现对于电子和传感器应用可能很重要，可避免内管与其他可能干扰其自身特性的物质发生不必要的接触。
