CAREER: Photochemistry at "Dirty" Ice Surfaces: Effects of Solutes on Reactivity

有了这个职业奖，化学系的环境化学科学项目资助锡拉丘兹大学的塔拉卡汉教授研究环境溶质对“脏”冰面化学反应性的影响;即包括常见环境溶质的表面。该项目的重点是将冰表面的物理特性与表面反应动力学联系起来。在冰表面的表面性质和反应动力学的存在和不存在常见的环境溶质，如卤化物盐和有机物的研究。这项研究的结果被用来预测雪和冰表面发生的化学反应对城市和偏远地区空气和水质量的影响。卡汉教授正在开发一个暑期讲习班，教中学生成为“科学记者”。研讨会的参与者采访了大气和环境科学家，并在锡拉丘兹的米尔顿J.鲁宾斯坦科学技术博物馆展示了基于这些采访的最终项目。这项工作的更广泛的科学影响包括改善了对积雪地区空气和水质量的预测，提高了中学生的科学素养和参与度。卡汉博士和她的同事们已经证明，常见的环境溶质可以极大地改变污染物在冰面上的命运，但溶质对冰化学的影响在很大程度上仍未得到探索。Kahan研究小组计划研究冰成分对光化学动力学和机制的影响。据设想，这些研究将提高预测雪和冰中的光化学对大气成分、污染物命运和气候的影响的能力。 具体目标是确定（i）常见溶质如卤化物和有机物（OM）如何在冰面上分布（荧光和拉曼显微术），（ii）常见的溶质如何影响有机污染物在冰面上的光解动力学和产物（荧光光谱和气相色谱-质谱）和（iii）常见溶质如何影响光化学产生和羟基自由基的归宿（OH）在冰面（色谱法，荧光光谱法和激光诱导荧光）。

With this CAREER award, the Environmental Chemical Sciences Program of the Division of Chemistry is funding Professor Tara Kahan of Syracuse University to investigate the effects of environmental solutes on chemical reactivity at "dirty" ice surfaces; i.e. surfaces which include common environmental solutes. The project focuses on relating physical properties of ice surfaces to surface reaction kinetics. Surface properties and reaction kinetics at ice surfaces are investigated in the presence and absence of common environmental solutes such as halide salts and organic matter. The results of this research are used to predict the impact of chemistry occurring at snow and ice surfaces on air and water quality in cities and in remote regions. A summer workshop being developed by Professor Kahan teaches middle-school children to be 'science journalists.' Workshop participants interview atmospheric and environmental scientists, and display final projects based on these interviews at the Milton J. Rubenstein Museum of Science and Technology in Syracuse. The broader scientific impacts of this work include improved predictions of air and water quality in snow-covered regions, and improved scientific literacy and engagement in middle-school children.Dr. Kahan and her coworkers have shown that common environmental solutes can greatly alter the fate of pollutants at ice surfaces, but the effects of solutes on ice chemistry remain largely unexplored. The Kahan research team plans to investigate the effects of ice composition on photochemical kinetics and mechanisms. It is envisioned that these studies will improve the ability to predict the effectsof photochemistry in snow and ice on atmospheric composition, pollutant fate, and climate. The specific objectives are to determine (i) how common solutes such as halides and organic matter (OM) are distributed at ice surfaces (fluorescence and Raman microscopy), (ii) how common solutes affect the photolysis kinetics and products of organic pollutants at ice surfaces (fluorescence spectroscopy and gas chromatography-mass spectrometry) and (iii) how common solutes affect the photochemical production and fate of hydroxyl radicals (OH)at ice surfaces (chromatography, fluorescence spectroscopy, and laser-induced fluorescence).