Heterogeneous Chemistry and Photochemistry in the Troposphere: Reactions of Mineral Dust and Other Metal-Containing Particle Surfaces at the Gas-Solid and Liquid-Solid Interface

美国国家科学基金会化学部的环境化学科学计划支持爱荷华大学Vicki H.Grassian教授的研究，该研究将侧重于矿物粉尘和金属颗粒在气固和液固界面上与微量大气气体的化学和光化学。在这些表面上发生的化学作用可以改变主要大气成分的气相浓度，也可以显著改变颗粒的物理化学性质。在环境中，这些界面既以气溶胶的形式存在，也以静止的表面存在。在拟议的研究中，研究了大气气体与矿物粉尘和含金属颗粒的成分的反应，以更好地了解对流层的化学物质以及这些反应对环境的影响。将研究几个不同的方面，包括有机酸与矿物粉尘颗粒的非均相化学、大气气体对矿物粉尘气溶胶的光活性成分的非均相化学以及作为大气气溶胶成分和静止表面的人为含金属氧化物颗粒的表面反应。这些反应在不同的水活度下进行，因此，水的不同相包括气-固界面上的吸附水和液-固界面上的液态水。拟议的活动侧重于更好地理解在气溶胶和静止颗粒表面发生的基本化学。如果没有这些类型的基础研究，就没有什么信息可以纳入大气和环境模型模拟，也就不会有什么人了解这种可能影响环境的潜在重要反应化学。除了与更好地了解自然和人类影响的环境有关的更广泛的影响外，这项研究的另一个重要组成部分是拟议的教育和外联活动。其中包括本科生和研究生的培养。PI有一个研究项目，吸引了不同的学生群体，包括许多女性和代表不足的少数族裔。外联活动包括为更广泛的公众开展亲身实践活动，覆盖了K-12学生及其家长。在爱荷华州大学文理学院的院系和中心内，该协会正在领导扩大和提高STEM(科学、技术、工程和数学)推广和教育的有效性的努力。

The Environmental Chemical Sciences Program in the Chemistry Division at the National Science Foundation supports the research of Professor Vicki H. Grassian at the University Iowa that will focus on the chemistry and photochemistry of mineral dust and metal-containing particles with trace atmospheric gases at the gas-solid and liquid-solid interface. The chemistry that occurs on these surfaces can alter gas phase concentrations of key atmospheric constituents as well as significantly change the physicochemical properties of the particles. In the environment, these interfaces are present as both aerosol and stationary surfaces. In the proposed studies, reactions of atmospheric gases with components of mineral dust and metal-containing particles are investigated to better understand the chemistry of the troposphere and the impact that these reactions have on the environment. Several different aspects will be investigated and include the heterogeneous chemistry of organic acids with mineral dust particles, the heterogeneous chemistry of atmospheric gases on photoactive components of mineral dust aerosol and surface reactions of anthropogenic metal-containing oxide particles, which are components of atmospheric aerosol as well as stationary surfaces. These reactions take place under different regimes of water activity and, therefore, different phases of water including adsorbed water at the gas-solid interface and liquid water at the liquid-solid interface.The proposed activities focus on better understanding the fundamental chemistry that occurs at aerosol and stationary particle surfaces. Without these types of fundamental studies, there would be little information to incorporate into atmospheric and environmental model simulations and there would be little understanding of this potentially important reaction chemistry that may impact the environment. Besides broader impacts related to better understanding the natural and human-impacted environment, another important component of this research is in the educational and outreach activities that are proposed. These include training of undergraduate and graduate students. The PI has a research program that attracts a diverse group of students including many women and underrepresented minorities. Outreach activities include the development of hands-on activities for the broader public that spans K-12 students and their parents. The PI is leading efforts to expand and enhance the effectiveness of STEM (Science, Technology, Engineering and Mathematics) outreach and education in departments and centers within the College of Liberal Arts and Sciences at the University of Iowa.