Reactions in Supercritical Fluids: Experimental and Simulation Studies of Microscopic Phenomena

超临界流体中的反应：微观现象的实验和模拟研究

基本信息

批准号：
9414759
负责人：
Theodore Randolph
金额：
$ 22.36万
依托单位：
University of Colorado at Boulder
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
1994
资助国家：
美国
起止时间：
1994-11-01 至 1998-10-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9414759&HistoricalAwards=false
关键词：
Reactions Supercritical Fluids Experimental Simulation

项目摘要

The microscopic phenomena which underlie experimental observations for reactivity of solutes dissolved in supercritical fluid solvents are not well understood. There is a wide variety of phenomena which may be implicated including solvent bulk properties, solvent accretion around solute molecules, and preferential clustering of solute molecules around one another. Reaction rates in general depend on both the solute collision frequency and the lifetime of each collision; the microscopic behavior may affect either or both. The engineering design of custom supercritical solvents for a given reaction will not be feasible without a detailed picture of how these effects combine to determine the reaction rate. The PI's plan to attack this problem on two fronts. First, a set of physical experimental studies will be undertaken, investigating both the macroscopic and the microscopic behavior as a function of bulk solvent properties, and utilizing several independent experimental techniques (local dielectric measurement, Heisenberg spin exchange). In concert with the physical measurements, computational experimental studies will be carried out with a view to supplying the experimentally inaccessible portions of the overall molecular picture, again using complementary techniques (Brownian dynamics, molecular dynamics). Each of the approaches will feed the development of the other, leading to an understanding of these systems using the applicable theory.

对溶解在超临界流体溶剂中的溶质的反应性进行实验观察的微观现象尚不清楚。可能涉及多种现象，包括溶剂本体特性、溶质分子周围的溶剂积聚以及溶质分子彼此优先聚集。反应速率通常取决于溶质碰撞频率和每次碰撞的寿命；微观行为可能会影响其中之一或两者。如果没有详细了解这些效应如何结合起来确定反应速率，则针对给定反应的定制超临界溶剂的工程设计将是不可行的。 PI 计划从两个方面解决这个问题。首先，将进行一系列物理实验研究，研究宏观和微观行为作为本体溶剂性质的函数，并利用几种独立的实验技术（局部介电测量、海森堡自旋交换）。与物理测量相一致，将进行计算实验研究，以提供整个分子图像中实验无法访问的部分，再次使用补充技术（布朗动力学、分子动力学）。每种方法都将促进另一种方法的发展，从而使用适用的理论来理解这些系统。