Nanostructured Macromolecules and Carbon-based Materials

本研究旨在探讨共轭高分子与单壁碳纳米管之间的选择性相互作用。目前，单壁碳纳米管在许多应用中的巨大技术前景，从柔性触摸屏到爆炸物或毒素的痕量传感器，由于难以纯化，分离和分散特定的纳米管类型，无法在商业规模上实现。最近，已经证明，共轭聚合物可以结合到单壁碳纳米管的表面，产生复合物，表现出溶解性和提高纯度。这种纳米管纯化方法很有前途，因为它可以很容易地和成本效益地扩大到工业水平。我们最近已经表明，共轭聚合物的电子性质可以决定他们的偏好与半导体（S）与金属（M）单壁碳纳米管相互作用。虽然富电子聚合物优选s-SWNT，但贫电子聚合物显示出对m-SWNT的偏好。现在的挑战是通过制造尽可能贫电子的共轭聚合物来增加分散的m-SWNT的纯度，这是该提案的目标之一。这将通过用吸电子基团修饰聚合物主链来实现。我们还将研究的方法，共轭聚合物可以从单壁碳纳米管表面去除后，选择性的相互作用和分离/纯化的纳米管已经发生。 这将通过制备结合到SWNT表面的可降解聚合物来完成，然后可以解聚回其原始单体组分（可以回收）。此外，我们将探讨与单壁碳纳米管的最佳相互作用所需的聚合物结构类型的基本问题，特别关注共轭聚合物是否实际上是必需的。我们将制备含有由非共轭链段分离的共轭单元的新结构，并将优化这些聚合物与单壁碳纳米管的相互作用。最后，我们将通过与共轭聚合物的超分子相互作用将分子识别元件连接到单壁碳纳米管表面，以赋予所得组装物以感官特性。 将准备传感器设备，并测量它们对国防和执法应用中感兴趣的特定分析物的反应。

This proposal aims to investigate the selective interactions between conjugated polymers and single-walled carbon nanotubes (SWNTs). Currently, the enormous technological promise of SWNTs in numerous applications, ranging from flexible touch screens to sensors for traces of explosives or toxins, cannot be realized on commercial scale because of difficulty in purifying, isolating, and dispersing specific nanotube types. Recently, it has been demonstrated that conjugated polymers can bind to the surface of SWNTs, producing complexes that exhibit solubility and enhanced purity. This approach to nanotube purification is promising as it can be easily and cost-effectively scaled up to industrial levels. We have recently shown that the electronic properties of conjugated polymers can dictate their preference for interacting with semiconducting (s) versus metallic (m) SWNTs. While electron-rich polymers prefer s-SWNTs, electron-poor polymers show a preference for m-SWNTs. Now the challenge is to increase the purity of m-SWNTs being dispersed by making conjugated polymers that are as electron-poor as possible, which is one of the goals of this proposal. This will be accomplished by decorating the polymer backbone with electron-withdrawing groups. We will also investigate methods by which conjugated polymers can be removed from the SWNT surface after selective interactions and separation/purification of nanotubes have taken place. This will be done by preparing degradable polymers that bind to the SWNT surface, and then can be depolymerized back to their original monomer components (which can be recycled). In addition, we will explore fundamental questions about the type of polymer structure that is needed for optimal interactions with SWNTs, with particular focus on whether conjugated polymers are actually required. We will prepare new structures that contain conjugated units separated by non-conjugated segments, and will optimize the interactions of these polymers with SWNTs. Finally, we will attach molecular recognition elements to the SWNT surface through supramolecular interactions with conjugated polymers in order to impart sensory properties to the resulting assemblies. Sensor devices will be prepared, and their response to specific analytes of interest in defence and law enforcement applications will be measured.