Density Gradient Ultracentrifugation of Nanotubes: Interplay of Bundling and Surfactants Encapsulation
Density Gradient Ultracentrifugation of Nanotubes: Interplay of Bundling and Surfactants Encapsulation
复制标题
纳米管的密度梯度超速离心：成束和表面活性剂封装的相互作用
DOI：
10.1021/jp1030174
复制
发表时间：
2010-10-21
影响因子：
3.7
通讯作者：
Ferrari, A. C.
中科院分区：
文献类型：
--
作者：
Bonaccorso, F.;Hasan, T.;Ferrari, A. C.
密度梯度超速离心法(DGU)是一种很有前途的手性富集型纳米管样品制备方法。在这里，我们评估不同的表面活性剂对DGU的性能。胆盐(如胆酸钠(SC)、脱氧胆酸钠(SDC)和牛磺酸脱氧胆酸钠(TDC))在单壁碳纳米管(SWNTs)的个体化方面比直链表面活性剂(如十二烷基苯磺酸钠(SDBS)和十二烷基硫酸钠(SDS))更有效，更适合DGU。与SDC和TDC相比，使用SC在CoMoCAT管上通过一次DGU步骤可以获得更窄的直径分布(0.69-0.81 nm)。使用SDBS不能获得选择性。由于其在拆分方面的不力。我们将二羟基胆盐(S、DC和TDC)相对于三羟基SC的还原选择性归因于二次胶束的形成。这是由类固醇主干A侧上羟基(OH)的数量和位置决定的。我们还使用Pluronic F98三嵌段共聚物在0.84-0.92 nm范围内浓缩CoMoCAT SWNT。胆盐(SC)和直链表面活性剂(SOS)的混合物被用于富集金属和半导体激光烧蚀生长的单壁碳纳米管。我们在CoMoCAT样品上展示了单一手性(6，5)的浓缩，结合了直径和金属与半导体的分离。
Density gradient ultracentrifugation (DGU) has emerged as a promising tool to prepare chirality enriched nanotube samples. Here, we assess the performance of different surfactants for DGU. Bile salts (e.g., sodium cholate (SC), sodium deoxycholate (SDC), and sodium taurodeoxycholate (TDC)) are more effective in individualizing Single Wall Carbon Nanotubes (SWNTs) compared to linear chain surfactants (e.g., sodium dodecylbenzene sulfonate (SDBS) and sodium dodecylsulfate (SDS)) and better suited for DGU. Using SC, a narrower diameter distribution (0.69-0.81 nm) is achieved through a single DGU step on CoMoCAT tubes, when compared to SDC and TDC (0.69-0.89 nm). No selectivity is obtained using SDBS. due to its ineffectiveness in debundling. We assign the reduce selectivity of dihydroxy bile salts (S DC and TDC) in comparison with trihydroxy SC to the formation of secondary micelles. This is determined by the number and position of hydroxyl ( OH) groups on the a-side of the steroid backbone. We also enrich CoMoCAT SWNT in the 0.84-0.92 nm range using the Pluronic F98 triblock copolymer. Mixtures of bile salts (SC) and linear chain surfactants (SOS) are used to enrich metallic and semiconducting laser-ablation grown SWNTs. We demonstrate enrichment of a single chirality, (6,5), combining diameter and metallic versus semiconductillg separation on CoMoCAT samples.