CAREER: Mesoscale Aggregation and Interfacial Dynamics in Ionic Liquids

职业：离子液体中的介观聚集和界面动力学

• 批准号: 1753282
• 负责人: Joshua Sangoro
• 金额: $ 62.5万
• 依托单位: University of Tennessee Knoxville
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-15 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1753282&HistoricalAwards=false
• 关键词: CAREER; Mesoscale; Aggregation; Interfacial; Dynamics

In this project funded by the Chemical Structure Dynamics and Mechanism (CSDM-A) program of the Chemistry Division, Professor Joshua Sangoro of The University of Tennessee, Knoxville is using advanced experimental techniques to study the structure of ionic liquids, which are liquids composed of positive and negative ions. Unlike ionic solids (such as table salt, Na+ Cl-), the fluid form of ionic liquids (also called molten salts) makes them potentially useful for a variety of technological applications, such as batteries, fuel cells and the solvents for the synthesis of other molecules. Just as liquid water actually contains areas that are ice-like in their ordering, ionic liquids can also possess local ordering of ionic molecules. The extent of ordering in ionic liquids influences their physical properties (e.g., density, viscosity, ability to conduct electricity). Professor Sangoro and his team seek to understand how ions organize in the liquid state, how long the arrangements persists, and how these arrangements are changed by interfaces such as the ionic liquid-air interface, or the interface between the liquid and a metal surface(where the metal may be a catalyst or an electrode for chemical reactions). The Sangoro group uses x-ray and neutron scattering techniques and a technique called broadband dielectric spectroscopy to obtain information about the structure and behavior of ionic liquids. This information may aid in the development of new clean energy and battery technologies. The main goal of the educational and outreach plans is to increase student interest in, exposure to, and preparation for careers in science and engineering, with specific focus on minority students. Professor Sangoro organizes mentored research experiences for high school students from underrepresented/minority and economically disadvantaged local groups, by first introducing engineering undergraduate students to research within the first two years of college. The research group partners with established NSF-funded outreach programs at the University of Tennessee to attract and retain engineering students from underrepresented groups, providing new research and training opportunities to graduate, undergraduate, and high school students in order to provide state-of-the-art research opportunities. Professor Sangoro engages in individualized mentoring for selected K-12 students from underrepresented groups in the economically disadvantaged groups living in the East Knoxville area. This CAREER grant enables the research team to provide hands-on training to both graduate and undergraduate students as well as high school students who may go on to become future scientists and engineers.The project focuses on understanding the impact of mesoscale organization on interfacial ion dynamics in bulk and confined molecular ionic liquids. Upon systematic variation of the chemical composition of ionic liquids, the mesoscale organization and dynamics are probed by x-ray and neutron scattering, dynamic mechanical spectroscopy, and broadband dielectric spectroscopy. These complementary techniques enable the correlation of mesoscale structures, and an understanding of their dynamics and the resulting physical and chemical properties of ionic liquids. The second emphasis of this research project is on elucidating the correlation between of mesoscale organization and dynamics within the electrochemical double layers in molecular ionic liquids. This effort involves development of a new theoretical model to describe the processes associated with accumulation of ions at interfaces between ions and solid electron conductors. The third thrust of the project focuses on experiments to understand the impact of geometric confinement on mesoscale organization and dynamics. To achieve this, silica nanopores with mean diameters as small as 4 nanometers are prepared through electrochemical etching and filled with systematic series of ionic liquids. The interactions between ionic liquids and the pore walls are intentionally varied while measuring the dynamics associated with the ions. The series of experiments and computations leads to a molecular-level understanding of the influence of mesoscopic organization on interfacial ion dynamics and transport in bulk and confined molecular ionic liquids. The fundamental understanding gained from these studies enables rational development of more efficient systems of ionic liquids for different applications including uses in electrochemical power sources and devices. The broader impacts of this work include potential societal benefits from an increased understanding of ionic liquids, as well as training of students and postdoctoral associates in fundamental science underlying many electrochemical energy 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.

在这个由化学学部化学结构动力学和机理（CSDM-A）项目资助的项目中，美国田纳西大学诺克斯维尔分校的Joshua Sangoro教授使用先进的实验技术研究离子液体的结构，离子液体是由正离子和负离子组成的液体。与离子固体（如食盐，Na+ Cl-）不同，离子液体（也称为熔盐）的流体形式使它们在各种技术应用中具有潜在的用途，例如电池，燃料电池和合成其他分子的溶剂。就像液态水实际上包含像冰一样有序的区域一样，离子液体也可以拥有离子分子的局部有序。离子液体的有序程度影响它们的物理性质（如密度、粘度、导电能力）。Sangoro教授和他的团队试图了解离子在液体状态下是如何组织的，这种排列持续多久，以及这些排列是如何被界面改变的，比如离子液-空气界面，或者液体和金属表面之间的界面（金属可能是化学反应的催化剂或电极）。Sangoro小组使用x射线和中子散射技术以及一种称为宽带介电光谱的技术来获取有关离子液体的结构和行为的信息。这些信息可能有助于开发新的清洁能源和电池技术。教育和推广计划的主要目标是提高学生对科学和工程职业的兴趣、接触和准备，特别关注少数民族学生。Sangoro教授通过首先在大学的前两年介绍工程本科学生进行研究，为来自代表性不足/少数民族和经济弱势群体的高中生组织指导研究经验。该研究小组与美国国家科学基金会资助的田纳西大学外展项目合作，从代表性不足的群体中吸引和留住工程专业的学生，为研究生、本科生和高中生提供新的研究和培训机会，以提供最先进的研究机会。教授桑戈罗从事个性化的指导，从代表性不足的群体在经济弱势群体中选择K-12学生生活在东诺克斯维尔地区。这项职业补助金使研究团队能够为研究生和本科生以及可能成为未来科学家和工程师的高中生提供实践培训。该项目的重点是了解中尺度组织对大块和受限分子离子液体界面离子动力学的影响。根据离子液体化学成分的系统变化，利用x射线和中子散射、动态力学光谱和宽带介电光谱对离子液体的中尺度组织和动力学进行了探测。这些互补的技术使中尺度结构的相关性，以及对它们的动力学和离子液体的物理和化学性质的理解成为可能。本研究的第二个重点是阐明分子离子液体中电化学双层内的中尺度组织与动力学之间的关系。这项工作包括开发一个新的理论模型来描述离子和固体电子导体之间界面上离子积累的过程。该项目的第三个重点是通过实验来了解几何约束对中尺度组织和动力学的影响。为了实现这一目标，通过电化学刻蚀制备了平均直径小至4纳米的二氧化硅纳米孔，并填充了系统系列的离子液体。在测量与离子相关的动力学时，离子液体与孔壁之间的相互作用是有意改变的。一系列的实验和计算使我们从分子水平上理解介观组织对大块和受限分子离子液体中界面离子动力学和输运的影响。从这些研究中获得的基本理解能够合理地开发更有效的离子液体系统，用于不同的应用，包括电化学电源和设备的使用。这项工作的更广泛的影响包括对离子液体的进一步了解所带来的潜在社会效益，以及对学生和博士后在许多电化学能源技术基础科学方面的培训。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。

项目成果

Ion dynamics in pendant and backbone polymerized ionic liquids: A view from high-pressure dielectric experiments and free-volume model

• DOI: 10.1103/physreve.105.054502
• 发表时间: 2022-05-09
• 期刊: PHYSICAL REVIEW E
• 影响因子: 2.4
• 作者: Cheng, Shinian;Wojnarowska, Zaneta;Paluch, Marian
• 通讯作者: Paluch, Marian

Localized and Collective Dynamics in Liquid-like Polyethylenimine-Based Nanoparticle Organic Hybrid Materials

• DOI: 10.1021/acs.macromol.0c02370
• 发表时间: 2021-02
• 期刊: Macromolecules
• 影响因子: 5.5
• 作者: E. Mapesa;N. Cantillo;Sara T. Hamilton;Matthew A Harris;T. Zawodzinski;Ah-Hyung Alissa Park;J. Sangoro-J.-S

Mesoscale Organization and Dynamics in Binary Ionic Liquid Mixtures

• DOI: 10.1021/acs.jpclett.9b02478
• 发表时间: 2019-10-17
• 期刊: JOURNAL OF PHYSICAL CHEMISTRY LETTERS
• 影响因子: 5.7
• 作者: Cosby, Tyler;Kapoor, Utkarsh;Sangoro, Joshua
• 通讯作者: Sangoro, Joshua