Vapor-Liquid-Ice: Exploring Water's Phase Transitions Far from Equilibrium

汽-液-冰：探索远离平衡状态的水的相变

• 批准号: 1900064
• 负责人: Barbara Wyslouzil
• 金额: $ 50万
• 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: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1900064&HistoricalAwards=false
• 关键词: Vapor; Liquid; Ice; Exploring; Water; Vapor; Liquid; Ice; Exploring; Water

With this award, the Chemical Structure, Dynamics and Mechanisms-A (CSDM-A) and Environmental Chemical Sciences (ECS) Programs of the Division of Chemistry are funding Professor Barbara Wyslouzil at Ohio State University (OSU) to exploring how water moves between the vapor, liquid and solid states. Two phenomena that are being studied are supercooled water and supersaturated water vapor. Liquid water generally changes into ice solid water) below 32 degrees Fahrenheit (0 degrees Celsius), but sometimes it remains in liquid form well below the freezing temperature (hence the name "supercooled"). Similarly, sometimes, water can remain in vapor form well above the concentration at which it should form a liquid (condense); this point is called "supersaturated." Professor Wyslouzil and her research team are using a supersonic nozzle, infrared spectroscopy, and x-ray scattering tools to determine the limits to which water vapor can be supersaturated and liquid water supercooled, and how fast the eventual freezing and condensation occur. These questions are important in the atmosphere where the state of water affects both the ability of clouds to bounce sunlight back into space and the chemical reactions taking place within the clouds. In industry, understanding when water condenses is important to developing efficient energy extraction schemes. Professor Wyslouzil participates in OSU's Breakfast of Science Champions program and collaborates with the Steam Factory, an OSU initiative to promote interdisciplinary collaboration across Science, Technology, Engineering, Arts, and Math.To investigate phase transitions involving supercooled and supersaturated water, the Wyslouzil group has developed a transportable supersonic nozzle apparatus that is easily integrated with a broad range of analytical tools. In her lab, standard methods include static pressure measurements to characterize the flow and infrared spectroscopy to quantify the distribution of the condensable fraction among the vapor, liquid and solid states. To fully characterize the size of the aerosol droplets and their crystal structure requires spatially resolved small- and wide- angle X-ray scattering (SAXS/WAXS) experiments and these are made at national user facilities. The high transformation rates that are measured also approach those that can be directly investigated using molecular simulations. Experiments, exploring how water far from equilibrium behaves and/or transforms, are critical to advancing our understanding of the phase diagram of water, the validity of advanced water models, the anomalous behavior of this fascinating compound, and for developingaccurate models of natural and industrial processes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

有了这个奖项，化学结构，动力学和机制-A（CSDM-A）和化学划分的环境化学科学（ECS）计划是为俄亥俄州立大学（OSU）的Barbara Wyslouzil教授提供资金，以探索水如何在蒸气，液态和固态之间移动。 正在研究的两个现象是超冷的水和过饱和的水蒸气。 液态水通常会变成冰水）低于32度的华氏度（0摄氏度），但有时它保持在液体形式中，远低于冻结温度（因此名称为“过冷”）。 同样，有时，水可能保持在蒸气中，远高于应形成液体的浓度（凝结）。这一点称为“过饱和”。 Wyslouzil教授和她的研究团队正在使用超音速喷嘴，红外光谱和X射线散射工具来确定水蒸气可以过饱和并过冷的限制，以及最终的冷冻和冷凝水的速度。这些问题在水状态在水状态下影响云的能力弹回阳光回太空的能力以及化学反应发生在云层内的大气中很重要。在行业中，了解水何时凝结对于制定有效的能源提取方案很重要。 Professor Wyslouzil participates in OSU's Breakfast of Science Champions program and collaborates with the Steam Factory, an OSU initiative to promote interdisciplinary collaboration across Science, Technology, Engineering, Arts, and Math.To investigate phase transitions involving supercooled and supersaturated water, the Wyslouzil group has developed a transportable supersonic nozzle apparatus that is easily integrated with a broad range of analytical tools.在她的实验室中，标准方法包括静压测量值，以表征流量和红外光谱，以量化蒸气，液体和固态之间可凝结分数的分布。为了充分表征气溶胶液滴的大小及其晶体结构需要空间分辨的小角度X射线散射（SAX/蜡）实验，并且这些实验是在国家用户设施中进行的。测量的高变换速率也接近可以使用分子模拟直接研究的速率。实验，探索水如何远离平衡的行为和/或变换，对于我们对我们对水相图的理解，高级水模型的有效性，这种迷人化合物的异常行为的理解至关重要 标准。