Multidimensional and Nonlinear Kinetics in Complex Materials

在化学测量和成像计划的支持下，以及化学结构，动力学和机制- A计划的共同资助下，南卡罗来纳州大学的Mark贝格教授和他的团队正在开发新的方法，用于探测当系统被强大的激光照射干扰时发生的化学变化。 该研究小组特别感兴趣的是系统对多重扰动的响应，而不是使用单一扰动的更传统的方法。 这些“多维”实验对于理解复杂材料是非常有用的，在复杂材料中，相同的分子可能会因其局部环境而改变其反应。 该研究的重点是使用超快激光脉冲扰动系统，然后监测非常快的响应（小于万亿分之一秒），从而在分子运动重组局部环境之前观察到反应的基本步骤。 贝格博士积极招募化学内外的本科生，以提供跨学科的研究经验。 研究生接受先进光学、光谱学、电子学和数据处理方法的培训。 贝格教授参与讲习班，使学生（特别是来自代表性不足群体的学生）熟悉研究生院的机会。 他还积极参与大学与少数民族研究生教育（GEM）奖学金计划之间的合作，旨在增加来自代表性不足群体的学生人数，他们继续在STEM领域进行研究生学习。 当许多液体冷却时，它们自发地形成微观结构，导致粘度非常迅速地增加。 多维光谱实验的目的是检查这些微结构的初始形成，看看它们是否足以解释所观察到的宏观性质的变化。 独立控制多达六个激光脉冲的偏振和相位，可以研究肥皂和洗涤剂产生的微观结构中的局部结构，流动性和反应动力学。 这些微结构的范围从简单的胶束，溶解水中的有机物质的复杂的双层膜，是无处不在的细胞。 贝格实验室为参与研究的研究生和本科生提供了一个高度跨学科的环境。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标准进行评估，被认为值得支持。

With support from the Chemical Measurement and Imaging program and co-funding from the Chemical Structures, Dynamics, and Mechanisms - A program, Professor Mark Berg and his group at the University of South Carolina are developing new methods for probing chemical changes that occur when a system is perturbed by illumination with powerful laser light. The research group is particularly interested in the response of a system to multiple perturbations, in contrast to more conventional approaches which use a single perturbation. These “multidimensional” experiments are uniquely useful for understanding complex materials where otherwise identical molecules may have their responses altered by their local environment. The research focuses on perturbing systems using ultrafast laser pulses then monitoring very fast responses (less than a trillionth of a second), enabling the elementary steps of a reaction to be observed before molecular motion reorganizes the local environment. Dr. Berg actively recruits undergraduates from both within and outside chemistry to provide a cross-disciplinary research experience. Graduate students are trained in advanced optics, spectroscopy, electronics and data-processing methods. Professor Berg is involved with workshops familiarizing students (especially those from underrepresented groups) with graduate school opportunities. He is also active in a partnership between the University and the Graduate Education for Minorities (GEM) Fellowship Program aimed at increasing the number of students from underrepresented groups who go on to graduate studies in STEM fields. As many liquids cool, they spontaneously form microstructures that lead to a very rapid increase in viscosity. Multidimensional spectroscopic experiments are designed to examine the initial formation of these microstructures to see if they are sufficient to explain the observed changes in macroscopic properties. Independent control of the polarization and phase of up to six laser pulses enables investigation of the local structure, fluidity and reaction dynamics in microstructures created by soaps and detergents. These microstructures range from simple micelles that solubilize organic materials in water to the complex bilayer membranes that are ubiquitous in cells. The Berg laboratory provides a highly interdisciplinary environment for graduate and undergraduate students involved in the research.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.