Growth Rate Dependence of Secondary Organic Aerosol on Seed Particle Size, Composition, and Phase
Growth Rate Dependence of Secondary Organic Aerosol on Seed Particle Size, Composition, and Phase
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DOI：
10.1021/acsearthspacechem.2c00049
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发表时间：
2022-08
影响因子：
3.4
通讯作者：
Devon N. Higgins;M. Taylor;J. Krasnomowitz;M. Johnston
中科院分区：
文献类型：
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作者：
Devon N. Higgins;M. Taylor;J. Krasnomowitz;M. Johnston
在流动管反应器中，经过一定的反应时间，测定了组分、粒径和相态对α-蒎烯臭氧分解超细种子颗粒生长的影响。在给定的一组条件下，模拟与时间相关的颗粒生长，可以确定反应生长因子（GF），它被定义为α-蒎烯分子反应产生生长颗粒的产物的比例。比较了新形成的α-蒎烯二级有机气溶胶（SOA）、浮肿硫酸铵和潮解硫酸铵组成的初始种子粒径为40、60和80 nm时的生长因子。总体而言，SOA种子颗粒的生长因子最低。脱出的硫酸铵颗粒具有较高的生长因子，对相对湿度有轻微的依赖性。潮解硫酸铵颗粒的生长因子最高。种子颗粒大小的依赖性表明，表面和体积限制的反应可能有助于生长。总的来说，在研究的反应条件下，生长因子的变化幅度超过4倍。这些结果强调了种子颗粒特征在决定与云凝结核形成有关的大小范围内的颗粒生长速率方面所起的关键作用。
The effects of composition, size, and phase state on ultrafine seed particle growth by α-pinene ozonolysis were determined from diameter growth measurements after a fixed reaction time in a flow tube reactor. Modeling time-dependent particle growth under a given set of conditions allowed the reaction growth factor (GF) to be determined, which is defined as the fraction of α-pinene molecules that react to give a product that grows the particles. Growth factors were compared for initial seed particle diameters of 40, 60, and 80 nm that were composed of freshly formed α-pinene secondary organic aerosol (SOA), effloresced ammonium sulfate, and deliquesced ammonium sulfate. Overall, SOA seed particles gave the lowest growth factors. Effloresced ammonium sulfate particles gave somewhat higher growth factors and showed a slight dependence on relative humidity. Deliquesced ammonium sulfate particles gave the highest growth factors. Seed particle-size dependencies suggested that both surface- and volume-limited reactions may contribute to growth. Overall, the growth factors were found to vary by more than 4x across the reaction conditions studied. The results highlight the crucial role that seed particle characteristics play in determining particle growth rates in a size range relevant to formation of cloud condensation nuclei.