Dyke Christopher A, Tour James M
Departments of Chemistry and Mechanical Engineering and Materials Science, and Center for Nanoscale Science and Technology, MS 222, Rice University, 6100 Main Street, Houston, Texas 77005, USA.
Chemistry. 2004 Feb 20;10(4):812-7. doi: 10.1002/chem.200305534.
The use of carbon nanotubes in materials applications has been slowed due to nanotube insolubility and their incompatibility with polymers. We recently developed two protocols to overcome the insoluble nature of carbon nanotubes by affixing large amounts of addends to the nanotube sidewalls. Both processes involve reactions with aryl diazonium species. First, solvent-free functionalization techniques remove the need for any solvent during the functionalization step. This delivers functionalized carbon nanotubes with increased solubility in organic solvents and processibility in polymeric blends. Additionally, the solvent-free functionalization process can be done on large scales, thereby paving the way for use in bulk applications such as in structural materials development. The second methodology involves the functionalization of carbon nanotubes that are first dispersed as individual tubes in surfactants within aqueous media. The functionalization then ensues to afford heavily functionalized nanotubes that do not re-rope. They remain as individuals in organic solvents giving enormous increases in solubility. This protocol yields the highest degree of functionalization we have obtained thus far-up to one in nine carbon atoms on the nanotube has an organic addend. The proper characterization and solubility determinations on nanotubes are critical; therefore, this topic is discussed in detail.
由于碳纳米管的不溶性及其与聚合物的不相容性，其在材料应用中的使用受到了阻碍。我们最近开发了两种方法来克服碳纳米管的不溶性，即在纳米管侧壁上附着大量添加剂。这两个过程都涉及与芳基重氮物种的反应。首先，无溶剂功能化技术在功能化步骤中无需任何溶剂。这使得功能化碳纳米管在有机溶剂中的溶解度增加，并且在聚合物共混物中具有可加工性。此外，无溶剂功能化过程可以大规模进行，从而为在结构材料开发等大量应用中的使用铺平了道路。第二种方法涉及对首先以单根形式分散在水性介质中的表面活性剂中的碳纳米管进行功能化。然后进行功能化，得到大量功能化的纳米管，这些纳米管不会重新缠结。它们在有机溶剂中以单个形式存在，溶解度大幅提高。该方法产生了我们迄今为止获得的最高功能化程度——纳米管上多达九分之一的碳原子带有有机添加剂。对纳米管进行适当的表征和溶解度测定至关重要；因此，将详细讨论这个主题。
