Using Amphiphilic Semiconducting Polymers to Control Structure and Exited State Dynamic in Conjugated Organic Assemblies

使用两亲性半导体聚合物控制共轭有机组件中的结构和激发态动态

• 批准号: 2003755
• 负责人: Sarah Tolbert
• 金额: $ 60万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2003755&HistoricalAwards=false
• 关键词: Using; Amphiphilic; Semiconducting; Polymers; Control

With this award, the Macromolecular, Supramolecular, and Nanochemistry Program in the Chemistry Division is supporting Professor Sarah H. Tolbert and her team at the University of California, Los Angeles (UCLA) to develop artificial photosynthesis systems to efficiently use light energy. The understanding gained from this research may allow the future production of inexpensive solar cells or the fabrication of devices that use sunlight to perform important chemical reactions. In photosynthesis in plants, light falling on a plant leaf causes an electron to be excited in a specific fashion, launching a chemical reaction sequence that the plant utilizes to capture carbon dioxide (CO2) reductively and convert CO2-moieties into the carbon atoms of the glucose. This project uses the same ideas to create a variety of artificial photosynthesis systems to efficiently harvest and utilize energy from visible light. The basic problem with artificial photosynthesis is that even though it is relatively easy to use light to energetically excite an electron, it is difficult to maintain the required state; electrons often return to their original starting point without performing useful chemistry. This work uses specially designed molecular systems that self-assemble into predetermined structures in water. Those structures control the motion of electrons after they are photo-excited to ensure that the desired chemical state is achieved. In addition to the potential scientific advances, this multidisciplinary project provides training for undergraduate and graduate students in areas of national need. The project also helps bring experiments on related topics of energy harvesting from sunlight and nanoscale materials to Los Angeles area high schools.Professor Tolbert’s team is examining the assembly of organic systems with intrinsic anisotropy, minimized charge recombination, and high light absorption. The project is a three-way collaboration among researchers who have complementary expertise in synthesizing the appropriate molecules (Yves Rubin - UCLA), in understanding the structure and self-assembly of these molecular systems (Sarah Tolbert - UCLA), and in monitoring the photodynamics and photochemistry of these assemblies (Benjamin Schwartz-UCLA). In biological photosynthetic systems, absorption of light leads to the requisite charge-separated state with nearly 100% quantum yield, thanks to evolutionary tuning of electron transfer cascades that spatially separate charges, preventing recombination. This project examines the creation of analogous artificial organic assemblies with intrinsic anisotropy, that are designed to minimize charge recombination while optimizing light absorption. One specific aim of this work is to synthesize a large family of amphiphilic electron-donating semiconducting polymers and amphiphilic small-molecule electron-acceptors that spontaneously form cylindrical micelles in aqueous solution. These molecules are made with a range of sizes, charges, electronic structures, and steric constraints, allowing them to self-assemble in a predictable manner according to specific hydrophobic and steric interactions. The next aim is to characterize the assemblies structurally and optically to understand the geometries that are created. The final aim is to study the assemblies spectroscopically and in functional opto-electronic devices to determine what design changes can further enhance the efficiency of charge-separation. Overall, these studies on the design and tuning of self-assembling light-harvesting polymers are expected to contribute to the development of artificial photosynthetic systems. In the longer term, advancements made through these foundational studies are expected to provide useful knowledge and insight for the fields of photovoltaics and photocatalysis.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.

凭借该奖项，化学部的高分子、超分子和纳米化学项目正在支持加州大学洛杉矶分校 (UCLA) 的 Sarah H. Tolbert 教授和她的团队开发人工光合作用系统，以有效利用光能。这项研究的成果可能有助于未来生产廉价的太阳能电池或制造利用阳光进行重要化学反应的设备。在植物的光合作用中，落在植物叶子上的光会导致电子被激发。以一种特定的方式，启动植物利用还原性捕获二氧化碳 (CO2) 并将 CO2 部分转化为葡萄糖的碳原子的化学反应序列。该项目使用相同的想法来创建各种人工光合作用系统，以有效地进行光合作用。人工光合作用的基本问题是，尽管利用光来激发电子相对容易，但电子通常很难保持所需的状态而无法执行。有用这项工作使用特殊设计的分子系统，在水中自组装成预定的结构，这些结构在光激发后控制电子的运动，以确保实现所需的化学状态。这个多学科项目为国家需要的领域的本科生和研究生提供培训。该项目还有助于将阳光和纳米材料能量收集相关主题的实验带到洛杉矶地区的高中。托尔伯特教授的团队正在研究有机系统的组装。和该项目是研究人员之间的三向合作，他们在合成适当的分子（Yves Rubin - 加州大学洛杉矶分校）方面拥有互补的专业知识，以了解这些分子系统的结构和自组装。 （莎拉·托尔伯特 - 加州大学洛杉矶分校），以及监测这些组件的光动力学和光化学（本杰明·施瓦茨 - 加州大学洛杉矶分校）在生物光合作用系统中，光的吸收导致。得益于电子转移级联的进化调谐，电子转移级联在空间上分离电荷，防止复合，从而达到所需的电荷分离状态，且量子产率接近 100%。该项目研究了具有内在各向异性的类似人造有机组件的创建，这些组件旨在最大限度地减少电荷。这项工作的一个具体目标是合成一大类两亲给电子半导体聚合物和两亲小分子。这些分子在水溶液中自发形成圆柱形胶束，具有一系列尺寸、电荷、电子结构和空间限制，使它们能够根据特定的疏水和空间相互作用以可预测的方式进行自组装。目的是从结构和光学角度表征组件，以了解所创建的几何形状，最终目标是通过光谱和功能光电器件研究组件。总体而言，这些关于自组装光捕获聚合物的设计和调整的研究预计将有助于人工光合作用系统的发展。通过这些基础研究，预计将为光伏和光催化领域提供有用的知识和见解。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查进行评估，被认为值得支持标准。

项目成果

Understanding the Effects of Confinement and Crystallinity on HJ-Coupling in Conjugated Polymers via Alignment and Isolation in an Oriented Mesoporous Silica Host

通过定向介孔二氧化硅基质中的排列和分离了解限制和结晶度对共轭聚合物中异质耦合的影响

• DOI: 10.1021/acs.jpcc.1c05844
• 发表时间: 2021
• 期刊: The Journal of Physical Chemistry C
• 作者: Winchell, K. J.;Voss, Matthew G.;Schwartz, Benjamin J.;Tolbert, Sarah H.
• 通讯作者: Tolbert, Sarah H.

Tunable Dopants with Intrinsic Counterion Separation Reveal the Effects of Electron Affinity on Dopant Intercalation and Free Carrier Production in Sequentially Doped Conjugated Polymer Films

• DOI: 10.1002/adfm.202001800
• 发表时间: 2020-05-25
• 期刊: ADVANCED FUNCTIONAL MATERIALS
• 影响因子: 19
• 作者: Aubry, Taylor J.;Winchell, K. J.;Schwartz, Benjamin J.
• 通讯作者: Schwartz, Benjamin J.

Counterion Control and the Spectral Signatures of Polarons, Coupled Polarons, and Bipolarons in Doped P3HT Films

• DOI: 10.1002/adfm.202213652
• 发表时间: 2023-02
• 期刊: Advanced Functional Materials
• 影响因子: 19
• 作者: Eric C Wu;Charlene Z. Salamat;O. Ruiz;Thomas Qu;Alexis Kim;S. Tolbert;B. J. Schwartz

Designing Amphiphilic Conjugated Polyelectrolytes for Self-Assembly into Straight-Chain Rod-like Micelles

• DOI: 10.1021/acs.macromol.2c02057
• 发表时间: 2023-04
• 期刊: Macromolecules
• 影响因子: 5.5
• 作者: K. J. Winchell;Patrick Y. Yee;Yolanda L. Li;Alexander F. Simafranca;Julia Chang;Christian Beren;Xinyu Liu;Diego Garcia Vidales;Robert Thompson;Charlene Z. Salamat;Quynh M. Duong;Robert S. Jordan;B. J. Schwartz;W. Gelbart;Y. Rubin;S. Tolbert

Controlling the Formation of Charge Transfer Complexes in Chemically Doped Semiconducting Polymers

• DOI: 10.1021/acs.chemmater.0c04471
• 发表时间: 2021-03
• 期刊: Chemistry of Materials
• 影响因子: 8.6
• 作者: Dane A. Stanfield;Yutong Wu;S. Tolbert;B. J. Schwartz