Collaborative Research: Impact of Aerosol Viscosity, Phase Separation, and Internal Structure on Isoprene-Derived SOA (Secondary Organic Aerosol) Formation

该项目致力于最大限度地缩小测量结果与表征大气中小有机颗粒物形成速率、浓度和空间分布的模型之间的差距。实验室研究将在气溶胶环境室设施中进行，以测量气溶胶和气相产品的关键物理化学特性。研究结果将用于改进二次有机气溶胶（SOA）形成的模型，以更好地为空气质量、人类健康和气候的政策决策提供信息。PI将检验较高粘度和相分离将抑制异戊二烯环氧二醇（IEPOX）反应性吸收的假设。测试该假设的实验计划的四个目标包括（1）确定作为颗粒粘度的函数的IEPOX的反应性摄取;（2）确定具有复杂形态的颗粒上的IEPOX的反应性摄取;（3）鉴定不同粘度和形态的IEPOX衍生的SOA组分的分子组成和物理化学性质;（4）确定不同粘度和形态的IEPOX衍生的SOA组分的分子组成和物理化学性质;（5）确定不同粘度和形态的IEPOX衍生的SOA组分的分子组成和物理化学性质;（6）确定不同粘度和形态的IEPOX衍生的SOA组分的分子组成和物理化学性质。和（4）由IEPOX的反应性吸收化学产生的挥发性产物的表征。

The project strives to minimize the gap between measurements and models that characterize the formation rates, concentrations, and spatial distributions of small organic particles in the atmosphere. Laboratory studies will be conducted in the UNC Environmental Chamber Facility to measure key physicochemical properties of aerosol and gas phase products. The results will be applied to improve models of secondary organic aerosol (SOA) formation to better inform policy decisions about air quality, human health, and climate.The PIs will test the hypothesis that higher viscosity and phase-separation will suppress the reactive uptake of isoprene epoxydiols (IEPOX). The four objectives of the experimental plan to test this hypothesis include the (1) determination of the reactive uptake of IEPOX as a function of particle viscosity; (2) determination of the reactive uptake of IEPOX on particles with complex morphologies; (3) identification of the molecular composition and physicochemical properties of the IEPOX-derived SOA constituents for different viscosities and morphologies; and (4) characterization of volatile products resulting from reactive uptake chemistry of IEPOX.