Ultrafast dynamics of supercritical fluid solutions

本课题由化学系化学结构、动力学和机理研究项目资助，由劳伦斯·D。波士顿大学的齐格勒将进行一系列实验，使用超快激光光谱方法来了解与普通液体相比，使超临界流体（SCF）成为如此有效溶剂的特殊性质。 这些研究旨在揭示数百飞秒到数百皮秒的时间尺度上的运动如何解释这种非凡的溶剂化能力。 将与波士顿大学的几位理论家合作，采用实验和计算相结合的方法来实现这些目标。 研究生和本科生将参与这项研究，并将接受最先进方法的培训。 此外，参加PROSTARS，NSF赞助的计划，以提高当地社区大学生的研究机会，并在NSF RET（研究经验的教师）计划，以及学生在韦尔斯利女子学院，将被鼓励参加这些研究在这个奖项的夏季月份。超临界流体被高度压缩，既不是气体也不是液体。 SCF具有气体和液体性质的独特且有用的组合。许多研究人员正在探索使用SCF来取代传统溶剂的方法，这些溶剂可能是有毒的，易燃的或难以去除的，因为它们溶解混合物，就像它们是液体一样，但很容易改变密度，因此可以更容易地去除或处理。 齐格勒教授的研究将帮助科学家了解是什么赋予了SCF这些不寻常的特性，以便它们可以更有效地使用，并在更广泛的应用中使用。

In this project, funded by the Chemical Structure, Dynamics and Mechanisms Program of the Chemistry Division, Professor Lawrence D. Ziegler of Boston University will conduct a series of experiments that use ultrafast laser spectroscopic methods to learn about the special properties that allow supercritical fluids (SCFs) to be such effective solvents, as compared to normal liquids. These studies are designed to reveal how motions on the time scale of hundreds of femtoseconds to hundreds of picoseconds account for this extraordinary solvation ability. A combined experimental and computational approach will be carried out to accomplish these goals in collaboration with several theorists at Boston University. Graduate and undergraduate students will participate in this research, and will be trained in state-of the-art methods. In addition, participants in PROSTARS, an NSF sponsored program to enhance research opportunities for local community college students, and in the NSF RET (Research Experience for Teachers) program, as well as students in the women's college of Wellesley, will be encouraged to participate in these studies during the summer months of this award. A supercritical fluid is so highly compressed that it is neither a gas nor a liquid. SCFs have unique and useful combinations of gas and liquid properties. Many investigators are exploring ways to use SCFs to replace traditional solvents, which can be toxic, flammable or difficult to remove, because they because they dissolve mixtures well as if they are liquids, but have easily changed densities and thus can be more easily removed or processed. Prof. Ziegler's research will help scientists understand what gives SCFs these unusual properties so that they can be used more effectively and in a wider range of applications.