RUI: Thermodynamics of Nucleation: From Water to Atmospheric Aerosols

有了这个奖项，化学系的环境化学科学项目资助了巴克内尔大学的乔治·希尔兹教授，以确定与大气气溶胶相关的分子复合物的结构和能量。这些复合物是由水分子、硫酸分子和大气中发现的其他微量分子形成的。这些复合物很重要，因为它们关系到云如何形成的基本基础，而云形成的机制目前尚不清楚。该项目还通过其持续和富有成效的本科研究经验模式产生了广泛的影响，该模式涉及同一批学生，包括少数民族和妇女，贯穿整个本科阶段。乔治·希尔兹教授和他的同事们正在进行一项联合计算/实验研究，以建立最小能量结构和氢键配合物形成的热力学。这些研究允许对最先进的计算化学方法的能力进行评估，以模拟可以直接比较的水簇，并帮助指导最先进的微波光谱实验。希尔兹小组正在确定含有硫酸、碱和水的分子团簇的结构和热力学，这些分子团簇被认为是中性和离子云凝聚核。这些方法有望预测所有潜在相关复合物的相对丰度，从而深入了解哪些复合物在云成核过程中对大气具有重要意义。从更广泛的意义上说，这里正在开发的技术可能为大气科学家提供将空气质量/成分与云核/模式发展联系起来的新方法。

With this award, the Environmental Chemical Sciences Program of the Division of Chemistry is funding Professor George Shields of Bucknell University to determine structures and energies of molecular complexes relevant to atmospheric aerosols. These complexes are formed from water molecules, sulfuric acid molecules, and other trace molecules found in the atmosphere. These complexes are important because they are relate to the fundamental basis of how clouds form, and the mechanism for cloud formation is currently not known. The project is also having a broad impact through its model of a sustained and productive undergraduate research experience involving the same students, including minorities and women, throughout their undergraduate years.Professor George Shields and co-workers are purusing a joint computational/experimental study toward establishing the minimum energy structures and the thermodynamics for formation of hydrogen-bonded complexes. These studies allow for the assessment of the ability of state-of-the-art computational chemistry methods to model water clusters that can be directly compared, and help guide state-of-the-art microwave spectroscopy experiments. The Shields group is determining the structures and thermodynamics of molecular clusters containing sulfuric acid, bases, and water, that are believed to serve as neutral and ionic cloud condensation nuclei. These methods are expected to allow for the prediction of the relative abundance of all potentially relevant complexes, providing insight on which ones are of atmospheric importance in the cloud nucleation process. In a much broader sense, the techniques being developed here may provide atmospheric scientists with new ways to relate air quality/composition to cloud nucleation/pattern development.