Control and Characterization of the Morphology and Photophysics of Conjugated Molecules in Isolation and in Aggregate

分离和聚集共轭分子的形态和光物理学的控制和表征

基本信息

批准号：
1807931
负责人：
Laura Kaufman
金额：
$ 62.05万
依托单位：
Columbia University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-01 至 2022-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1807931&HistoricalAwards=false
关键词：
Control Characterization Morphology Photophysics Conjugated

项目摘要

Polymers are long chains of hundreds or thousands of molecules, called monomers. When many polymer chains are aggregated together they form plastics, whose properties depend on the monomer's chemical structure. While some polymers are made to be stiff or flexible, others are designed to absorb light, transport excited state energy (called excitons), and conduct electricity, giving rise to electronic devices that are thin, light, and flexible. While such polymers have been known for some time, designing materials that have the same performance as traditional electronics materials (e.g. silicon) is difficult. The movement of excitons through a polymer involves both motion along a single chain, as well as transfer between chains, and studying this interchain hopping is a challenge. With funding from the Macromolecular, Supramolecular, and Nanochemistry Program in the Division of Chemistry, Professor Laura Kaufman at Columbia University is using sophisticated microscopies to study the flow of excitons through polymer aggregates. The insights gained from the project could help pave the way to inexpensive solar cells and flexible electronics, which would have significant societal benefits. The project is also providing training opportunities for graduate and undergraduate students, who will enter the Nation's science and technology workforce, and Professor Kaufman and her students are engaging with local elementary school students to promote interest in scientific exploration and discovery. The project is exploring the excited state properties of individual polymer chains, as well as polymers that are organized together as aggregates. The focus is on polyfluorenes, perylene diimides, and polyacenes, each of which are promising for optoelectronic applications. Professor Kaufman and her students use approaches recently developed in her laboratory to control the assembly of single polymer chains into aggregates of particular size and structure through variation in solvent mixture and swelling. Preparation of aggregates of different packing densities is accomplished by careful selection of molecular properties and by tuning the aggregation to be driven by Ostwald ripening or coalescence. Spectroscopic properties (e.g. absorption, emission, anisotropy) are characterized on chromophore-by-chromophore basis using polarization modulation and super-resolution microscopies, which provide a detailed picture of the correlation between polymer conformation and excited state photophysical properties. Through the combination of controlled aggregate formation and detailed spectroscopic measurement, the research team is attempting to ascertain whether morphological ordering on mesoscopic length scales can be used to tune exciton diffusion length and other photophysical characteristics of aggregates.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.

聚合物是数百或数千个分子的长链，称为单体。当许多聚合物链聚集在一起时，它们形成塑料，其性质取决于单体的化学结构。虽然某些聚合物是僵硬或柔韧的，但其他聚合物的设计旨在吸收光线，运输激发的状态能量（称为激子）并进行电力，从而产生薄，轻巧且柔性的电子设备。尽管此类聚合物已经闻名了一段时间，但设计与传统电子材料（例如硅）具有相同性能的材料很困难。激子通过聚合物的运动既涉及沿单个链的运动，又涉及链之间的转移，并且研究这种链跳跃是一个挑战。在化学系的大分子，超分子和纳米化学计划的资金中，哥伦比亚大学的劳拉·考夫曼教授正在使用复杂的显微镜来研究激子通过聚合物聚集体的流动。从该项目中获得的见解可以帮助铺平道路廉价的太阳能电池和灵活的电子产品，这将具有重大的社会利益。该项目还为研究生和本科生提供了培训机会，他们将进入该国科学和技术劳动力，考夫曼教授和她的学生正在与当地的小学生互动，以促进对科学探索和发现的兴趣。该项目正在探索单个聚合物链的激发状态特性，以及作为聚集体一起组织的聚合物。重点是聚氟烯，甲基二酰亚胺和聚酸烯，每个聚糖对于光电应用有望。考夫曼教授和她的学生使用最近在她的实验室开发的方法来控制单个聚合物链的组装，以通过溶剂混合物和肿胀的变化来控制特定尺寸和结构的聚集体。通过仔细选择分子特性，并调整由Ostwald成熟或合并驱动的聚集来完成不同填料密度的聚集体的制备。光谱特性（例如吸收，发射，各向异性）在逐赋形剂基础上使用极化调节和超分辨率显微镜在逐行的逐行小组基础上进行了表征，这些显微镜提供了聚合物构象与激发态光体特性之间相关性的详细相关图。通过将受控的骨料形成和详细的光谱测量结合在一起，研究团队试图确定是否可以使用对介质长度尺度上的形态学排序来调整ICCITON扩散长度和其他骨料的光体物理特征。认为值得通过基金会的智力优点和更广泛影响的评论标准来评估值得支持。