Field-Flow Fractionation (FFF) as an Integral Experiment in Junior Physical Chemistry Labs

场流分级 (FFF) 作为初级物理化学实验室的一个完整实验

• 批准号: 9751589
• 负责人: Paul Schettler
• 金额: $ 1.65万
• 依托单位: Juniata College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-07-01 至 1999-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9751589&HistoricalAwards=false
• 关键词: Field; Flow; Fractionation; FFF; Integral

This project incorporates field-flow fractionation (FFF) into the physical chemistry laboratory. This relatively new technique is rapidly gaining acceptance as a method for separating and characterizing macromolecules and particles with diameters ranging from 0.002 to 100 micrometers in diameter. The method is superficially similar to chromatography, but the basis of separation in FFF is the interaction of particle flow down a channel with an external field applied perpendicular to the direction of flow. Separation occurs because particles differ in their tendency to be forced into slow carrier streamlines adjacent to the channel wall. Besides being a new and promising technique, FFF is an ideal vehicle for introducing students to an experimental investigation of transport properties. For example, in normal mode flow FFF, the retention time of an eluted particle depends on the diffusion constant of that particle. Diffusion measurements have been made for macromolecules and other particles over the wide range of 0.002 to 1 micrometer. This project adopts FFF diffusion constant measurement as the primary nonequilibrium component of the junior-level physical chemistry laboratory. It joins experiments that characterize porous solids, measure activity coefficients electrochemically, ascertain enthalpies of combustion or solution, and establish rate constants of chemical reactions. Addition of the proposed FFF experiment also complements these exercises with one that is computer controlled. *

该项目将场流分馏（FFF）纳入物理化学实验室。 这种相对较新的技术作为一种用于分离和表征直径范围为0.002至100微米的大分子和颗粒的方法正在迅速获得认可。 该方法表面上类似于色谱法，但FFF中分离的基础是沿通道向下的颗粒流与垂直于流动方向施加的外部场的相互作用。 分离的发生是因为颗粒在它们被迫使进入通道壁附近的慢载流子流线的倾向上不同。 除了是一种新的和有前途的技术，FFF是一个理想的工具，为学生介绍了一个实验研究的输运性质。 例如，在正常模式流FFF中，洗脱颗粒的保留时间取决于该颗粒的扩散常数。 扩散测量已在0.002至1微米的宽范围内的大分子和其他颗粒。 本项目采用FFF扩散常数测量作为初级物理化学实验室的主要非平衡组成部分。 它加入了表征多孔固体的实验，电化学测量活度系数，确定燃烧或溶液的性质，并建立化学反应的速率常数。 增加拟议的FFF实验也补充了这些练习，其中一个是计算机控制的。 *