Collaborative Research: Kinetics and Mechanism of Restructuring of Atmospheric Soot and Associated Impact on Light Absorption

纳米颗粒大气烟尘颗粒的形状、大小和化学成分都很复杂。它们可以被不同地观察为分形聚集体，由元素碳（石墨或石墨烯结构中的EC-）或有机碳化合物（氧化或其他附着杂原子部分的OC -碳氢化合物）组成。其他气溶胶物质可能在内部或外部混合状态下嵌入或缠绕，如烟灰颗粒在周围大气中老化。我们对烟尘混合状态、烟尘形态和烟尘光学性质之间的关系了解有限，这仍然是评估碳质气溶胶对直接辐射气候强迫的光学和辐射贡献的主要不确定性来源。研究人员将进行一系列实验室和计算相结合的研究，以更好地表征不同混合状态下烟灰颗粒的形成，并研究与颗粒初始状态和气溶胶老化有关的相关结构和光学特性。混合状态和形态的烟灰聚集体将确定从质量迁移率测量和环境扫描电子显微镜成像的组合。光学计算受实验测量的混合状态和形态的限制，将提供一个直接确定的光吸收和散射的范围内的碳烟。这项工作的一个更广泛的影响将是促进博士学位授予大学和主要本科教学大学的教师之间的合作。

Nanoparticulate atmospheric soot particles are complex in their shape, size and chemical composition. They can be variably observed as fractal aggregates composed of elemental carbon (EC- in graphitic or graphene structures), or organic carbon compounds (OC - hydrocarbons with oxidized or other attached heteroatom moieties). Other aerosol materials potentially embed or enmesh, in either internal or external mixing states, such soot particles as they age in the ambient atmosphere. Our limited knowledge of relationships between soot mixing state, soot morphology, and soot optical properties, remains a major source of uncertainty in evaluating the optical and radiative contribution of carbonaceous aerosols to direct radiative) climate forcing. Researchers will undertake a series of combined laboratory and computational studies to better characterize the formation of soot particles with different mixing states, and to investigate associated structural and optical properties in relation to the particle initial state and aerosol aging. Mixing states and morphology of soot aggregates will be determined from a combination of mass-mobility measurements and environmental scanning electron microscopy imaging. Optical calculations constrained by the experimentally measured mixing states and morphologies will provide a closure with directly determined light absorption and scattering by this range of carbonaceous soot.One broader impact of this work will be the promotion of collaboration between faculty at a PhD-granting and a primarily undergraduate teaching university.