Studies of Heterogeneous Nucleation of Ice in Thin Films

密歇根理工大学的Will Cantrell教授得到了分析与表面化学项目和物理气象项目的支持，研究微粒形成冰核的分子尺度机制。将采用两类外来物质（有机薄膜和不溶性固体表面）作为研究应变调节和结晶缺陷在成核过程中的相对作用的方法。所提出的实验旨在探讨经典成核理论的假设，如临界胚的作用，底物形态对成核的影响以及界面区域结构水分子的作用。红外光谱学将以衰减全反射或变体、衰减内反射光谱学的形式使用。研究生和本科生将接受涉及化学、物理和大气科学的跨学科研究领域的教育。在气溶胶颗粒上或内部形成冰仍然是大气中最不为人所知的现象之一。更好的理解将有助于更好地预测降水以及大气气溶胶变化对云和气候的影响。这个长期存在的问题需要仔细的实验和先进的理论来充分解决。

Professor Will Cantrell of the Michigan Technological University is supported by the Analytical and Surface Chemistry Program and the Physical Meteorology Program to investigate the molecular-scale mechanisms responsible for the nucleation of ice by particulates. Two classes of foreign substances are to be employed (organic films and insoluble solid surfaces) as a way of interrogating the relative roles of strain accommodation and crystalline defects in the nucleation process. The proposed experiments are designed to probe assumptions of classical nucleation theory such as the role played by the critical embrio, the effect on nucleation of the substrate morphology and the role of structured water molecules in the interfacial region. Infrared spectroscopy will be used in the form of attenuated total reflectance or a variant, attenuated internal reflection, spectroscopy. Graduate and undergraduate students will be educated this interdisciplinary research area involving chemistry, physics and atmospheric science.Ice formation on or within aerosol particles remains as one of the most poorly understood phenomena in the atmosphere. An improved understanding will allow better predictions of precipitation and the effects of changes in atmospheric aerosols on clouds and climate. This long-standing problem will require careful experimentation coupled with advanced theory to adequately address it.