Nucleation Studies with Sulfuric Acid (H2SO4) and Nitrogenous Bases

本项目涉及硫酸及其共反应物水、氨和胺的均相成核的实验室研究。目的是：(1)测量由胺和硫酸在一系列条件下形成的颗粒的成核速率，使用散装源流反应器；(2)利用光化学源对实验流动反应器进行表征，并在低硫酸浓度下测量几种胺的成核速率；(3)开发和使用流动反应器的计算流体动力学（CFD）模拟；(4)开发使用胺源和检测技术。实验室结果将与CFD模拟进行比较，CFD模拟详细处理了酸碱团簇的化学性质，从而得出酸碱团簇形成的热力学信息。成核是大气中新粒子形成的驱动力。新形成的粒子可以作为云凝结核，在大气气溶胶对气候的间接影响中发挥重要作用。该项目的最终目标是测试可纳入全球气候模型的成核率模型。本科学生将参与实验设备的建设，运行实验，建立数学模型，分析数据和撰写出版物。

This project involves laboratory investigations of homogeneous nucleation on sulfuric acid and its co-reactants water, ammonia and amines. The objectives are to: (1) measure the nucleation rate of particles formed from amines and sulfuric acid over a range of conditions with a bulk source flow reactor; (2) characterize the experimental flow reactor with a photo-chemical source for sulfuric acid and nucleation rate measurements for a few amines at low sulfuric acid concentrations, (3) develop and use computation fluid dynamic (CFD) simulations of the flow reactors, and (4) develop the use of amine sources and detection techniques. The laboratory results will be compared to CFD simulations that treat the cluster chemistry in detail, yielding thermodynamic information for the formation of acid-base clusters.Nucleation is the driving force for new particle formation in the atmosphere. Newly formed particles can serve as cloud condensation nuclei, important for their role in the indirect effect of atmospheric aerosols on climate. The ultimate goal of this project is to test models for nucleation rates that can be incorporated into global climate models. Undergraduate students will participate in the construction of laboratory apparatuses, running experiments, developing mathematical models, analyzing data, and authoring publications.