Nanostructured Macromolecules and Carbon-based Materials

本研究旨在研究共轭聚合物与单壁碳纳米管（SWNTs）之间的选择性相互作用。目前，由于难以净化、分离和分散特定的纳米管类型，swnt在从柔性触摸屏到爆炸物或毒素痕迹传感器等众多应用中的巨大技术前景无法实现商业规模。最近，已经证明共轭聚合物可以结合到单壁碳纳米管表面，产生具有溶解性和提高纯度的配合物。这种纳米管净化方法很有前途，因为它可以很容易地、经济有效地扩大到工业水平。我们最近表明，共轭聚合物的电子性质可以决定它们与半导体(s)和金属(m) SWNTs相互作用的偏好。富电子聚合物偏爱s-SWNTs，而贫电子聚合物偏爱m-SWNTs。现在的挑战是通过制造尽可能少电子的共轭聚合物来增加分散的m- swnt的纯度，这也是本提案的目标之一。这将通过用吸电子基团修饰聚合物主链来实现。我们还将研究在选择性相互作用和纳米管分离/纯化后共轭聚合物从SWNT表面去除的方法。这将通过制备可降解的聚合物来完成，这些聚合物与SWNT表面结合，然后可以解聚回其原始的单体成分（可以回收）。此外，我们将探讨与单壁碳纳米管最佳相互作用所需的聚合物结构类型的基本问题，特别关注是否实际上需要共轭聚合物。我们将制备包含由非共轭段分隔的共轭单元的新结构，并将优化这些聚合物与swcnts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附加到SWNT表面，以赋予所得到的组装的感官特性。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.