Solubilization of single-walled carbon nanotubes by using polycyclic aromatic ammonium amphiphiles in water--strategy for the design of high-performance solubilizers.
Solubilization of single-walled carbon nanotubes by using polycyclic aromatic ammonium amphiphiles in water--strategy for the design of high-performance solubilizers.
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DOI：
10.1002/chem.200501176
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发表时间：
2006-05
期刊：
影响因子：
--
通讯作者：
Yasuhiko Tomonari;H. Murakami;N. Nakashima
中科院分区：
文献类型：
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作者：
Yasuhiko Tomonari;H. Murakami;N. Nakashima
我们描述了具有高性能的多环芳香族化合物的设计，可溶解单壁碳纳米管（SWNTs）。合成的两亲体三甲基-（2-氧-2-苯乙基）-溴化铵(1)和三甲基-（2-萘-2-基-2-氧-乙基）-溴化铵(2)携带一个苯基或一个萘基片段，不能在水中溶解/分散单壁碳纳米管。相比之下，三甲基-（2-氧-2-菲-9-基乙基）-溴化铵(3)可增溶SWNTs，尽管增溶能力低于三甲基-（2-氧-2-芘-1-基乙基）-溴化铵(4)（文献4a简要描述了使用4观察到的增溶行为）。利用透射电子显微镜（TEM）、可见光/近红外光谱、荧光光谱和近红外光致发光光谱研究了4在水中的增溶性能，并与十二烷基硫酸钠（SDS）和十六烷基三甲基溴化铵（HTAB）作为增溶剂得到的结果进行了比较。在温和的实验条件下，化合物4对制备的单壁碳纳米管（原单壁碳纳米管）和纯化的单壁碳纳米管均有增溶作用，且增溶能力优于SDS和HTAB。近红外光致发光测试表明，溶解在4水溶液中的单壁碳纳米管的手性指数与用SDS和HTAB胶束得到的手性指数有很大不同；对于单壁碳纳米管/4溶液，（7,6）、（9,5）和（12,1）指数强度较强，手性分布较胶束溶液窄。这表明4的水溶液更倾向于溶解直径在0.89 ~ 1.0 nm范围内的半导体SWNTs，比溶解在SDS和HTAB水胶束中的SWNTs （0.76 ~ 0.97 nm）要大。
We describe the design of polycyclic aromatic compounds with high performance that dissolve single-walled carbon nanotubes (SWNTs). Synthetic amphiphiles trimethyl-(2-oxo-2-phenylethyl)-ammonium bromide (1) and trimethyl-(2-naphthalen-2-yl-2-oxo-ethyl)-ammonium bromide (2) carrying a phenyl or a naphtyl moiety were not able to dissolve/disperse SWNTs in water. By contrast, trimethyl-(2-oxo-2-phenanthren-9-yl-ethyl)-ammonium bromide (3) solubilized SWNTs, although the solubilization ability was lower than that of trimethyl-(2-oxo-2-pyrene-1-yl-ethyl)-ammonium bromide (4) (solubilization behavior observed by using 4 was described briefly in reference 4a). Transmission electron microscopy (TEM), as well as visible/near-IR, fluorescence, and near-IR photoluminescence spectroscopies were employed to reveal the solubilization properties of 4 in water, and to compare these results with those obtained by using sodium dodecyl sulfate (SDS) and hexadecyltrimethylammonium bromide (HTAB) as solubilizers. Compound 4 solubilized both the as-produced SWNTs (raw-SWNTs) and purified SWNTs under mild experimental conditions, and the solubilization ability was better than that of SDS and HTAB. Near-IR photoluminescence measurements revealed that the chiral indices of the SWNTs dissolved in an aqueous solution of 4 were quite different from those obtained by using micelles of SDS and HTAB; for a SWNTs/4 solution, the intensity of the (7,6), (9,5), and (12,1) indices were strong and the chirality distribution was narrower than those of the micellar solutions. This indicates that the aqueous solution of 4 has a tendency to dissolve semiconducting SWNTs with diameters in the range of 0.89-1.0 nm, which are larger than those SWNTs (0.76-0.97 nm) dissolved in the aqueous micelles of SDS and HTAB.