Collaborative Research: The role of interactions between organic components on aerosol hygroscopicity

该奖项的全部或部分资金来自《2021年美国救援计划法案》(公法117-2)。本项目的目标是研究在无机硫酸铵存在的情况下，混合有机组分对气溶胶吸湿性的影响。PI假设，有机-有机相互作用的系统差异将影响水吸收、活化和随后液滴形成过程中的溶解过程，并将改变化合物分配到液滴表面的能力，影响水的吸收和云凝结核(CCN)的活动。这项研究将改进对气溶胶对辐射强迫和气候的直接和间接影响的预测。这一提议的假设是，由经历液-液相分离的有机化合物硫酸铵和另一种有机化合物组成的体系的形态变化将取决于附加有机化合物的溶解度和表面活性。随着第二种有机化合物浓度的变化，颗粒的形态会发生变化，导致理论吸湿率与测量吸湿率之间的差异。PIS建议对以下系统进行描述：(1)硫酸铵和一种不具有表面活性的高度溶解有机化合物的混合物；(2)硫酸铵和表面活性有机化合物的混合物；(3)硫酸铵和高表面活性有机化合物(表面活性剂)的混合物。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). The goal of this project is to characterize the impact of mixed organic fractions on the hygroscopicity of aerosol in the presence of inorganic ammonium sulfate. The PIs postulate that the systematic differences in organic-organic interactions will impact the dissolution process during water uptake, activation, and subsequent droplet formation and will modify the ability of compounds to partition to the droplet surface, influencing water uptake and cloud condensation nuclei (CCN) activity. This research will improve predictions of the direct and indirect effects of aerosols on radiative forcing and climate.The hypothesis of this proposal is that changes to the morphology of a system consisting of ammonium sulfate, an organic compound that undergoes liquid-liquid phase separation, and an additional organic compound will depend on the solubility and surface activity of the additional organic compound. As the concentration of the second organic compound is varied, the particles’ morphology will change, causing differences between theoretical and measured hygroscopicity. The PIs propose to characterize the following systems: (1) mixtures of ammonium sulfate and a highly soluble organic compound that is not surface active; (2) mixtures of ammonium sulfate and a surface-active organic compound; and (3) mixtures of ammonium sulfate and a highly surface-active organic compound (surfactant).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.