Exciton Transport in Individual Nanotubular J-Aggregates

本项目以超分子有机体系中激子能量输运的研究为目标，通过对单个纳米管状J-聚集体的光谱研究，将其用作模型捕光系统。菁染料如C8S3在水溶液中自组装，形成直径13纳米、长度几微米的纳米管状超分子组装。这些纳米管类似于绿色硫磺细菌中天然捕光复合体的高效天线系统，因此是研究准一维激子系统捕光的一个有吸引力的模型。使用激光光谱、近场扫描光学显微镜(NSOM)和允许探测单个纳米管的共聚焦显微镜的组合来研究这些J聚集体。此外，荧光成像被用来直接测量单个纳米管聚集体中的能量转移的空间程度，以了解超分子有机系统中的激子输运。该项目产生了一些更广泛的社会影响：从事化学研究的学生的数量和多样性增加，开发和传播用于非均质材料的纳米尺度表征的工具，分子电子学，以及扩大对光收集的理解，因为光收集与利用太阳能有关。教育努力利用德克萨斯大学奥斯汀分校的新生研究倡议(FRI)，该计划旨在将有能力的、代表不足的学生群体带入研究实验室，否则他们可能不会选择研究作为职业目标。该奖项由化学系高分子、超分子和纳米化学项目颁发，获奖者是德克萨斯大学奥斯汀分校的大卫·范登·布特。

This project targets the study of exciton energy transport in supramolecular organic systems by means of spectroscopic investigation of individual nanotubular J-aggregates used as a model light-harvesting system. Cyanine dyes such as C8S3 self-assemble in aqueous solution to form nanotubular supramolecular assemblies that are 13 nm in diameter and several microns in length. These nanotubes are similar to the highly efficient antenna systems of the natural light-harvesting complexes in Green Sulfur Bacteria and are thus attractive as a model for studying light harvesting in quasi-one-dimensional excitonic systems. These J-aggregates are studied using a combination of laser spectroscopy, near-field scanning optical microscopy (NSOM), and confocal microscopy that allows probing of individual nanotubes. Additionally, fluorescence imaging is used to directly measure the spatial extent of energy transfer in individual nanotubular aggregates to understand exciton transport in supramolecular organic systems. The project has a number broader societal impacts: an increase in the number and diversity of students pursuing chemical research, the development and dissemination of tools for nanoscale characterization of heterogeneous materials, molecular electronics, and an expanded understanding of light harvesting as it pertains to harnessing solar energy. Educational efforts leverage the Freshman Research Initiative (FRI) at UT-Austin, a program designed to bring capable underrepresented student populations that might otherwise not chose research as a career goal into the research laboratories. This award is made by the Macromolecular, Supramolecular and Nanochemistry program of the Division of Chemistry and the recipient is David Vanden Bout of the University of Texas at Austin.