Hydrocarbon Thin Films as Models for Organic Aerosols

通过这个新的奖项，有机和大分子化学项目支持了科罗拉多大学博尔德分校化学系的G. Barney Ellison博士的工作。这项工作将包括研究表面活性剂分子（如硬脂酸、油酸或1-油酰-2-棕榈酰-3-磷酸胆碱）的单层膜在NaCl上镀和羟基自由基轰击（由氩气中H2O的电晕放电产生，并通过静电六极过滤），在O2、NO、SO2或O3等大气气体存在下的氧化。在真空室中，对表面的反应进行红外和紫外光谱分析，并用残余气体分析仪测量释放的任何小分子。所提出的研究中要研究的反应，涉及固体NaCl上薄有机层的氧化，是海洋上大气气溶胶颗粒外表面发生的反应的模型，在海洋上，生物表面活性剂分子包裹着由海洋喷雾形成的盐水液滴。了解其中的化学成分对于模拟气溶胶颗粒在云的形成、全球变暖和臭氧消耗中的作用非常重要。

With this new award the Organic and Macromolecular Chemistry Program supports the work of Dr. G. Barney Ellison of the Department of Chemistry at the Universito of Colorado in Boulder. The work will involve studying the oxidation of monolayer films of surfactant molecules (such as stearic acid, oleic acid, or 1-oleoyo-2-palmitoyl-3-phosphatyclcholine) plated on NaCl and bombarded with hydroxyl radicals (generated by a corona discharge of H2O in Ar and filtered by an electrostatic hexapole), in the presence of atmospheric gases such as O2, NO, SO2, or O3. Reactions at the surface will be followed by infrared and ultraviolet spectroscopies in a vacuum chamber, and any small molecules emitted measured with a residual gas analyzer. The reactions to be studied in the research proposed, involving the oxidation of thin organic layers on solid NaCl, are models for the reactions taking place on the outer surfaces of atmospheric aerosol particles over oceans, where biogenic surfactant molecules coat brine droplets formed from ocean spray. Understanding the chemistry is important for modeling the roles of aerosol particles in cloud formation, global warming, and ozone depletion.