CAREER: Bifacial Cyclophanes for Solution-Phase Synthesis of Semiconducting Porous Nanoribbons

在化学系大分子、超分子和纳米化学（MSN）项目的支持下，乔治城大学的Nagarjuna Gavvalapalli教授设计并开发了自下而上合成半导体多孔纳米带（SPNRs）的策略。受自然界β-薄片设计的启发，Gavvalapalli教授的团队设计了新的单体，可以通过控制条带宽度、电导率和孔径，实现自底向上合成spnr。SPNRs结合了半导体的晶体管特性和纳米孔的传感和筛选能力。它们可用于高通量转运检测、感知疾病的多种生物标志物和能量转换等应用。该项目有助于培训、教育和激励各种各样的人，包括来自服务不足的科学社区的高中生、本科生和公众。Gavvalapalli教授开发并使用了一个“超级英雄科学解释”项目，以挖掘人们对超级英雄的兴趣和好奇心，从而轻松地与来自不同背景的更广泛的受众建立联系。与传统的固态纳米孔相比，有机spnr具有几个优点，包括单原子厚度和可调节孔径、形状和化学功能的合成适应性。然而，目前的自顶向下的方法并不适合生成具有上述应用所需的纳米带和孔尺寸以及化学和电子结构控制的spnr。Gavvalapalli教授的团队提出的工作为SPNRs设计了新颖的构建单体，并开发了自下而上和溶液相合成SPNRs的设计规则，控制了条带和孔隙尺寸以及它们的化学和电子结构。这些单体被设计成阻碍链间范德华相互作用，并提供可溶液处理的spnr。该研究的三个主要目标集中在：i)改变单体设计参数以产生可溶的线性聚合物，为SPNRs的溶解度提供指导；ii)识别和控制线性聚合物的结构参数，这些参数在将其转化为SPNRs中起关键作用；iii)合成不同纳米带宽度、孔径和电子性质的SPNRs，研究其对SPNRs光物理和电子性质的影响。这项研究为迄今为止难以捉摸的纳米孔膜提供了途径。获得的特别方案清单使上述技术能够发生革命性的变化，并为新技术铺平道路。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Macromolecular, Supramolecular and Nanochemistry (MSN) Program in the Division of Chemistry, Professor Nagarjuna Gavvalapalli at Georgetown University designs and develops strategies for bottom-up synthesis of semiconducting porous nano-ribbons (SPNRs). Inspired from the β-sheets design in nature, Professor Gavvalapalli’s group designs novel monomers to enable bottom-up synthesis of SPNRs with control over their ribbon width, conductivity and pore size. SPNRs combine the transistor properties of semiconductors with the sensing and sieving capabilities of nanopores. They can be potentially useful for applications such as high-throughput transport detection, sensing multiple biomarkers of a disease, and energy conversion. The project contributes toward training, educating, and inspiring a diverse group of people including high-school students from underserved communities in science, undergraduate students, and the public. Professor Gavvalapalli develops and uses a “Superhero Scienceplanation” program to tap into people’s interest in and curiosity for superheroes in order to easily connect with a broader audience from diverse backgrounds. Organic SPNRs have several advantages, including single-atom-thickness and synthetic amenability to tune pore size, shape, and chemical functionality compared to traditional solid-state nanopores. However, the current top-down approaches are not suitable for generating SPNRs with control over the nanoribbon and pore dimensions as well as their chemical and electronic structure that are desirable for the above-mentioned applications. The proposed work in Professor Gavvalapalli’s group designs novel building block monomers for SPNRs and develops design rules for bottom-up and solution-phase synthesis of SPNRs with control over the ribbon and pore dimensions as well as their chemical and electronic structure. The monomers are designed such that they hinder interchain van der Waals interactions and render solution processable SPNRs. The three main objectives of the research are focused on: i) varying the monomer design parameters to generate soluble linear-polymers that provide guidelines for SPNRs solubility; ii) identifying and controlling the linear-polymer structural parameters that play a key role in transforming them into SPNRs; and iii) synthesizing SPNRs of various nanoribbon width, pore size, and electronic nature and studying their impact on the photophysical and electronic properties of SPNRs. This research provides access to nanoporous membranes that have been elusive so far. The obtained SPNRs enable transformative changes to above-mentioned technologies and also pave the way to new technologies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.