New Nonlinear Optical Approaches for Probing the Microscopic Nature of Liquids and Solutions

用于探测液体和溶液微观性质的新非线性光学方法

• 批准号: 1800491
• 负责人: John Fourkas
• 金额: $ 47.75万
• 依托单位: University of Maryland, College Park
• 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 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1800491&HistoricalAwards=false
• 关键词: New; Nonlinear; Optical; Approaches; Probing

When we think of a chemical reaction, we often envision a beaker filled with a solution and sitting on a lab bench. Most chemistry takes place in solution, where the liquid surrounding the reactants and products can affect a chemical reaction in unexpected ways. While chemists have appreciated the complicated nature of solutions for some time, they do not typically consider the container's size to be a factor. This is true of the container is large. However, when the container holding the solution is reduced to just a few hundred nanometers across, or about 1/10,000 the diameter of a human hair, interaction of molecules with the walls of the container alter the solution properties, making the problem even more difficult. With support for the Chemical Structure Dynamics, and Mechanisms A (CSDM-A) Program in the Division of Chemistry, Professor John Fourkas at the University of Maryland-College Park is developing new experimental and simulation methods for characterizing solutions, both in large containers, and under nanoconfinement. Insights gained from the project could advance our fundamental understanding of solutions, as well as enable more accurate measurements, both of which could have broad implications for range of technologies such as chemical separations, lubrication, oil recovery, and catalysis. The project also provides interdisciplinary training of the next generation of scientists, and outreach activities are fostering public appreciation of scientific exploration and discovery. New nonlinear optical spectroscopic approaches are being pursued to address important outstanding problems in liquids and solutions. Working with his students, Professor Fourkas is combining Optical Kerr effect (OKE) spectroscopy with molecular simulations to develop a general approach for measuring the intrinsic density of liquids in nanoconfined environments, which is a crucial property in determining the behavior of a liquid, as well as to study hydrogen bonding interactions between solvents and silica surfaces. The project is also pursuing substantially improved measurements of the high-intensity optical absorption properties of solutions of strongly absorbing molecules and nanomaterials. A new class of methods, 2-beam action (2-BA) spectroscopies, is being developed to make improved measurements of multiphoton absorption cross sections. 2-BA spectroscopies allow for the detailed and accurate characterization of the photophysics of multiphoton fluorophores, and set the stage for the application of analogous techniques to a broad range of other processes that involve nonlinear absorption.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.

当我们想到化学反应时，我们通常会想象一个装满溶液的烧杯放在实验室工作台上。大多数化学反应发生在溶液中，其中反应物和产物周围的液体可以以意想不到的方式影响化学反应。虽然化学家已经认识到溶液的复杂性有一段时间了，但他们通常不认为容器的大小是一个因素。这是真的容器是大的。 然而，当容纳溶液的容器缩小到只有几百纳米宽，或约为人类头发直径的1/10，000时，分子与容器壁的相互作用会改变溶液的性质，使问题变得更加困难。在化学系的化学结构动力学和机制A（CSDM-A）计划的支持下，马里兰大学帕克分校的John Fourkas教授正在开发新的实验和模拟方法，用于表征大型容器和纳米约束下的溶液。从该项目中获得的见解可以促进我们对解决方案的基本理解，并实现更准确的测量，这两者都可能对化学分离，润滑，石油回收和催化等一系列技术产生广泛的影响。 该项目还为下一代科学家提供跨学科培训，外联活动正在培养公众对科学探索和发现的认识。新的非线性光学光谱方法正在寻求解决重要的突出问题，在液体和解决方案。Fourkas教授与他的学生合作，将光学克尔效应（OKE）光谱与分子模拟相结合，开发出一种测量纳米封闭环境中液体固有密度的通用方法，这是确定液体行为的关键特性，以及研究溶剂和二氧化硅表面之间的氢键相互作用。该项目还致力于大幅改进对强吸收分子和纳米材料溶液的高强度光吸收特性的测量。一种新的方法，双束作用（2-BA）光谱学，正在开发，使多光子吸收截面的测量改进。2-BA光谱允许多光子荧光团的光物理学的详细和准确的表征，并设置了一个阶段，为应用类似的技术，以广泛的其他过程，涉及非线性吸收。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

项目成果

Methods for Determining the Effective Order of Absorption in Radical Multiphoton Photoresists: A Critical Analysis

• DOI: 10.1002/lpor.202000203
• 发表时间: 2020-11
• 期刊: Laser & Photonics Reviews
• 影响因子: 11
• 作者: N. Liaros;J. Fourkas

The Role of Resonant Coupling in Vibrational Sum-Frequency-Generation Spectroscopy: Liquid Acetonitrile at the Silica Interface

• DOI: 10.1016/j.molliq.2023.121315
• 发表时间: 2023-01
• 期刊: Journal of Molecular Liquids
• 影响因子: 6
• 作者: Amanda J. Souna;S. Cohen;Christopher A. Rivera;K. Manfred;B. Coasne;J. Fourkas

Extracting accurate information from triplet–triplet annihilation upconversion data with a mass-conserving kinetic model

使用质量守恒动力学模型从三重态-三重态湮灭上转换数据中提取准确的信息

• DOI: 10.1039/d2cp03986a
• 发表时间: 2022
• 期刊: Physical Chemistry Chemical Physics
• 影响因子: 3.3
• 作者: Kalpattu, Abhishek;Dilbeck, Tristan;Hanson, Kenneth;Fourkas, John T.
• 通讯作者: Fourkas, John T.

Structure and Dynamics of Acetonitrile: Molecular Simulation and Neutron Scattering

• DOI: 10.1016/j.molliq.2021.118423
• 发表时间: 2021-12
• 期刊: Journal of Molecular Liquids
• 影响因子: 6
• 作者: S. Cohen;M. Plazanet;S. Rols;D. Voneshen;J. Fourkas;B. Coasne