Nanodroplets to nanoparticles: Integretated studies of freezing

纳米液滴到纳米粒子：冷冻的综合研究

• 批准号: 1213959
• 负责人: Barbara Wyslouzil
• 金额: $ 47.84万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1213959&HistoricalAwards=false
• 关键词: Nanodroplets; nanoparticles; Integretated; studies; freezing

This award, funded by the Chemical Structure, Dynamics and Mechanisms program of the Division of Chemistry, supports the research of Prof. Barbara Wyslouzil and her students at The Ohio State University. The overarching goal of the proposed research is to explore the physics of freezing including the limits to which liquids can be supercooled, the transformation kinetics and the structure of the emerging solid phase. This research integrates experimental and molecular modeling. The specific experimental objectives include: 1) measurement of liquid-solid nucleation rates as nanodroplets freeze, 2) the exploration of the role of molecular structure on the relative importance of the surface versus bulk freezing and 3) the development to x-ray scattering techniques to follow the transformations in situ. Molecular modeling is used to understand the driving force for the surface freezing in chain-like molecules and to calculate liquid-solid nucleation rates to compare directly to the measured values. Freezing, or crystallization from the melt, is a fundamental physical process that plays a central role in a broad range of industrial and natural processes. Developing a deeper understanding of this phenomenon, measuring phase transition rates and exploring the role free surfaces play in freezing are all crucial for developing accurate models of industrial processes, atmospheric chemistry and global climate.In a broader context, this work develops novel applications of small angle scattering, aerosol spectroscopy, and molecular modeling techniques that address fundamental problems in aerosol science. The results stemming from this work are of interest to researchers in nucleation, polymer physics, materials science, and aerosol and cloud physics. The program provides a rich and varied research environment for students, from high school to graduate level that is highly interdisciplinary.

该奖项由化学系化学结构、动力学和机理项目资助，支持俄亥俄州立大学Barbara Wyslouzil教授和她的学生的研究。拟议研究的主要目标是探索冻结的物理，包括液体可以过冷的极限、转变动力学和新出现的固相的结构。本研究将实验和分子模拟相结合。具体的实验目标包括：1)测量纳米液滴冻结时的液-固成核速率，2)探索分子结构对表面与整体冻结的相对重要性的作用，以及3)发展X射线散射技术以跟踪原位转变。分子模拟是用来理解链状分子表面冻结的驱动力，并计算液-固成核速率，以便直接与测量值进行比较。冷冻，或从熔体中结晶，是一种基本的物理过程，在广泛的工业和自然过程中发挥着核心作用。加深对这一现象的理解，测量相变率，探索自由表面在冻结中所起的作用，对于开发准确的工业过程、大气化学和全球气候模型都是至关重要的。在更广泛的背景下，这项工作开发了小角散射、气溶胶光谱和分子模拟技术的新应用，以解决气溶胶科学中的基本问题。这项工作的结果引起了成核、聚合物物理、材料科学、气溶胶和云物理的研究人员的兴趣。该项目为从高中到研究生的学生提供了一个丰富多样的研究环境，具有高度跨学科的特点。

项目成果

How Cubic Can Ice Be?

• DOI: 10.1021/acs.jpclett.7b01142
• 发表时间: 2017-07-20
• 期刊: JOURNAL OF PHYSICAL CHEMISTRY LETTERS
• 影响因子: 5.7
• 作者: Amaya, Andrew J.;Pathak, Harshad;Wyslouzil, Barbara E.
• 通讯作者: Wyslouzil, Barbara E.