Developing the Molecular Underpinnings for Mechanisms of Growth of Secondary Organic Aerosol (SOA) Particles in Air

该项目涉及导致大气中二次有机气溶胶(SOA)形成和生长的过程。这些非常小的颗粒是由植物排放的气态生物碳氢化合物氧化形成的。这项研究的结果将为大气模型中的SOA过程的参数化提供指导。该项目的具体目标是：(1)在一系列实验条件下，将具有不同性质的示踪剂(如官能团和蒸汽压)量化到由不同的气相前体形成的SOA中；(2)测量从不同的SOA中输入到所提出的分子模型中的各种示踪剂的解吸速率；(3)利用萃取电喷雾电离质谱仪阐明SOA颗粒的表面区的性质；以及(4)测量不同结构的胺对固体二元酸和SOA的摄取系数的大小、时间依赖关系和机理。

This project addresses the processes that lead to the formation and growth of secondary organic aerosol (SOA) in the atmosphere. These very small particles are formed from the oxidation of gaseous biogenic hydrocarbons, emitted by plants. The results of this research will provide guidance for parameterizing SOA processes in atmospheric models.The specific objectives of the project are to: (1) quantify incorporation of tracers with different properties such as functional groups and vapor pressures into SOA formed from various gas phase precursors under a range of experimental conditions; (2) measure rates of desorption of various tracers from different SOA for input into a proposed molecular model; (3) elucidate the nature of the surface region of SOA particles using extractive electrospray ionization mass spectrometry; and (4) measure the magnitude, time dependence and mechanism of uptake coefficients for amines of different structures on solid diacids and SOA.