Nanodroplet Aerosols: Formation and Structure

纳米液滴气溶胶：形成和结构

• 批准号: 0410037
• 负责人: Barbara Wyslouzil
• 金额: $ 14.47万
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-11-15 至 2005-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0410037&HistoricalAwards=false
• 关键词: Nanodroplet; Aerosols; Formation; Structure

In this project funded by the Physical Chemistry Program of the Chemistry Division, Barbara Wyslouzil of the Worcester Polytechnic Institute will pursue a program of research on nanodroplet aerosols. The formation of liquid droplets in aerosols will be studied with a view to measuring and understanding nucleation from a phase transition perspective. Small angle neutron scattering (SANS) will be used to experimentally monitor particle size and composition and structure, and infrared (IR) measurements will be used to aid in the compositional analysis during nucleation and droplet formation. The research program is two pronged. First, a deeper understanding of phase transitions under conditions that are far from equilibrium will be obtained. Very high cooling rates insure that nuleation and condensation (phase transition) occur under highly supersaturated conditions. Intrinsic size distribution data from SANS measurements are expected to provide the first direct experimental measurements of nucleation rates in nozzles. Second, the internal structure of multi-component droplets will be discerned. The compositional and structural data will be used to test various models for the droplet structure. Key among the compositional factors to be examined is the degree to which immiscible phases mix and the clarity with which phase boundaries develop between immiscible liquids. This project will lead to a deeper understanding of how multicomponent droplets form. The results of the work will benefit society in helping to understand the physical chemistry of droplet nucleation, and this knowledge will benefit weather and climate studies and industrial processes based upon aerosol droplet formation. The work also will have a high impact on teaching undergradute and graduate students advanced materials science experimental and analysis techniques.

在这个由化学学部物理化学项目资助的项目中，伍斯特理工学院的Barbara Wyslouzil将进行纳米液滴气溶胶的研究项目。本文将研究气溶胶中液滴的形成，以期从相变的角度来测量和理解成核。小角中子散射（SANS）将用于实验监测颗粒的大小、组成和结构，红外（IR）测量将用于帮助分析成核和液滴形成过程中的成分。这项研究计划是双管齐下的。首先，对远离平衡状态下的相变有了更深入的了解。非常高的冷却速率确保在高度过饱和的条件下发生成核和冷凝（相变）。SANS测量的固有尺寸分布数据有望提供喷嘴成核速率的第一个直接实验测量。其次，识别多组分液滴的内部结构。组成和结构数据将用于测试液滴结构的各种模型。要检查的组成因素中的关键是不混相混合的程度和不混相液体之间相界发展的清晰度。这个项目将导致对多组分液滴如何形成的更深入的理解。这项工作的结果将有利于社会理解液滴成核的物理化学过程，这些知识将有利于基于气溶胶液滴形成的天气和气候研究以及工业过程。这项工作也将对本科生和研究生的高级材料科学实验和分析技术的教学产生重大影响。