Experimental studies of molecular kinetics, structure, and thermodynamic properties of pure and doped amorphous solid water at temperatures above 160 K

160 K 以上温度下纯和掺杂非晶固体水的分子动力学、结构和热力学性质的实验研究

• 批准号: 1012692
• 负责人: Vladislav Sadtchenko
• 金额: $ 24.66万
• 依托单位: George Washington University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1012692&HistoricalAwards=false
• 关键词: Experimental; studies; molecular; kinetics; structure

In this project supported by the Chemical Structure, Dynamics and Mechanisms Program of the Division of Chemistry, Professor Vladislav Sadtchenko of the George Washington University and his graduate and undergraduate students are investigating the structure and dynamics of deeply supercooled water and aqueous solutions using calorimetric, optical and mass spectroscopic techniques. The novel experimental approach relies on rapid heating of pure and doped amorphous solid water films vapor-deposited on a substrate at cryogenic temperatures. The rapid heating employed in such experiments makes it possible to avoid significant crystallization of the aqueous films and thus to study water in so-called "No Man's Land" temperature range, i.e., where data on water's properties is lacking. The principle goals of the research are: 1) to facilitate development of a comprehensive fundamental description of thermodynamics and molecular kinetics of water by providing experimental data on it s properties in a previously inaccessible temperature range, 2) to gain insights into the molecular kinetics and structure of water in the presence of various hydrated chemical species, and 3) to reconcile often conflicting results of the past experimental studies of supercooled water. Due to the ubiquitous presence of water in nature and its role in a multitude of environmental, biological, and industrial processes, the result of these studies will have an impact on a great variety of applied fields of science. The research activities are also important for advancement of the scientific method. Potential application of the fast scanning calorimetry technique in research on other (non-aqueous) systems are numerous and may include studies of the relaxation phenomena in polymers and other commercially significant materials. The proposed research activities will contribute to personnel development in the US by providing research training of a graduate (Ph.D.) and several undergraduate students. The broader impact of the work will also be achieved through a public outreach program in the greater Washington DC area.

在这个由化学系化学结构、动力学和机制计划支持的项目中，乔治华盛顿大学的Vladislav Sadtchenko教授和他的研究生和本科生正在使用量热、光学和质谱技术研究深度过冷水和水溶液的结构和动力学。新的实验方法依赖于快速加热的纯和掺杂的无定形固体水膜气相沉积在低温下的基板上。在这样的实验中采用的快速加热使得可以避免水性膜的显著结晶，从而研究所谓的“无人区”温度范围内的水，即，缺乏关于水的属性的数据。研究的主要目标是：1）通过提供关于水在以前无法获得的温度范围内的性质的实验数据，促进水的热力学和分子动力学的全面基本描述的发展，2）深入了解在各种水合化学物质存在下水的分子动力学和结构，3）调和过去过冷水实验研究中经常相互矛盾的结果。由于水在自然界中的普遍存在及其在许多环境，生物和工业过程中的作用，这些研究的结果将对各种应用科学领域产生影响。研究活动对科学方法的进步也很重要。快速扫描量热法技术在其他（非水）系统研究中的潜在应用是众多的，可能包括聚合物和其他商业上重要的材料中的弛豫现象的研究。拟议的研究活动将通过提供研究生（博士）培训，促进美国的人才培养。还有几个本科生这项工作的更广泛影响也将通过在大华盛顿特区地区的公共宣传计划来实现。